A VLSI Architecture for Video Object Motion Estimation Using a 2D Hierarchical Mesh Model

This paper proposes a novel hierarchical mesh-based video object model and a motion estimation architecture that generates a content-based video object representation. The 2D mesh-based video object is represented using two layers: an alpha plane and a texture. The alpha plane consists of two layers: (1) a mesh layer and (2) a binary layer that defines the object boundary. The texture defines the object’s colors. A new hierarchical adaptive structured mesh represents the mesh layer. The proposed mesh is a coarse-to-fine hierarchical 2D mesh that is formed by recursive triangulation of the initial coarse mesh geometry. The proposed technique reduces the mesh code size and captures the mesh dynamics. The proposed motion estimation architecture generates a progressive mesh code and the motion vectors of the mesh nodes. The performance analysis for the proposed video object representation and the proposed motion estimation architecture shows that they are suitable for very low bit rate online mobile applications and the motion estimation architecture can be used as a building block for MPEG4 codec.

Wael Badawy, “A VLSI Architecture for Video Object Motion Estimation Using a 2D Hierarchical Mesh Model,” Microprocessors and Microsystems, Vol. 27, No. 3, April 2003, pp 131 – 140, invited.



By Oliver Wendell Holmes, Jr.


The doctrine of contract has been so thoroughly remodelled to meet the needs of modern times, that there is less here than elsewhere for historical research. It has been so ably discussed that there is less room here elsewhere for essentially new analysis. But a short of the growth of modern doctrines, whether necessary or not, will at least be interesting, while an analysis of their main characteristics cannot be omitted, and may present some new features.

It is popularly supposed that the oldest forms of contract known to our law are covenant and debt, and they are of early date, no doubt. But there are other contracts still in use which, although they have in some degree put on modern forms, at least suggest the question whether they were not of equally early appearance.

One of these, the promissory oath, is no longer the foundation of any rights in private law. It is used, but as mainly as a solemnity connected with entering upon a public office. The judge swears that he will execute justice according to law, the juryman that he will find his verdict according to law and the evidence, the newly adopted citizen that he will bear true faith and allegiance to the government of his choice.

But there is another contract which plays a more important part. It may, perhaps, sound paradoxical to mention the contract of suretyship. Suretyship, nowadays, is only an accessory obligation, which presupposes a principal undertaking, and which, so far as the nature of the contract goes, is just like any other. But, as has been pointed out by Laferriere, /1/ and very likely by earlier writers, the surety of ancient law was the hostage, and the giving of hostages was by no means confined to international dealings.

In the old metrical romance of Huon of Bordeaux, Huon, having killed the son of Charlemagne, is required by the Emperor to perform various seeming impossibilities as the price of forgiveness. Huon starts upon the task, leaving twelve of his knights as hostages. /2/ He returns successful, but at first the Emperor is made to believe that his orders have been disobeyed. Thereupon Charlemagne cries out, “I summon hither the pledges for Huon. I will hang them, and they shall have no ransom.” /3/ So, when Huon is to fight a duel, by way of establishing the truth or falsehood of a charge against him, each party begins by producing some of his friends as hostages.

When hostages are given for a duel which is to determine the truth or falsehood of an accusation, the transaction is very near to the giving of similar security in the trial of a cause in court. This was in fact the usual course of the Germanic procedure. It will be remembered that the earliest appearance of law was as a substitute for the private feuds between families or clans. But while a defendant who did not peaceably submit to the jurisdiction of the court might be put outside the protection of the law, so that any man might kill him at sight, there was at first no way of securing the indemnity to which the plaintiff was entitled unless the defendant chose to give such security. /1/

English customs which have been preserved to us are somewhat more advanced, but one of the noticeable features in their procedure is the giving of security at every step. All lawyers will remember a trace of this in the fiction of John Doe and Richard Roe, the plaintiff’s pledges to prosecute his action. But a more significant example is found in the rule repeated in many of the early laws, that a defendant accused of a wrong must either find security or go to prison. /2/ This security was the hostage of earlier days, and later, when the actions for punishment and for redress were separated from each other, became the bail of the criminal law. The liability was still conceived in the same way as when the bail actually put his own body into the power of the party secured.

One of Charlemagne’s additions to the Lex Salica speaks of a freeman who has committed himself to the power of another by way of surety. /3/ The very phrase is copied in the English laws of Henry I. /4/ We have seen what this meant in the story of Huon of Bordeaux. The Mirror of Justices /5/ says that King Canute used to judge the mainprisors according as the principals when their principals not in judgment, but that King Henry I. confined Canute’s rule to mainprisors who were consenting to the fact.

As late as the reign of Edward III., Shard, an English judge, after stating the law as it still is, that bail are a prisoner’s keepers, and shall be charged if he escapes, observes, that some say that the bail shall be hanged in his place. /1/ This was the law in the analogous case of a jailer. /2/ The old notion is to be traced in the form still given by modern writers for the undertaking of bail for felony. They are bound “body for body,” /3/ and modern law-books find it necessary to state that this does not make them liable to the punishment of the principal offender if he does not appear, but only to a fine. /4/ The contract also differed from our modern ideas in the mode of execution. It was simply a solemn admission of liability in the presence of the officer authorized to take it. The signature of the bail was not necessary, /5/ and it was not requisite that the person bailed should bind himself as a party. /6/

But these peculiarities have been modified or done away with by statute, and I have dwelt upon the case, not so much as a special form of contract differing from all others as because the history of its origin shows one of the first appearances of contract in our law. It is to be traced to the gradual increase of faith in the honor of a hostage if the case calling for his surrender should arrive, and to the consequent relaxation of actual imprisonment. An illustration may be found in the parallel mode of dealing with the prisoner himself. His bail, to whom his body is supposed to be delivered, have a right to seize him at any time and anywhere, but he is allowed to go at large until surrendered. It will be noticed that this form of contract, like debt as dealt with by the Roman law of the Twelve Tables, and for the same motive, although by a different process, looked to the body of the contracting party as the satisfaction.

Debt is another and more popular candidate for the honors of priority. Since the time of Savigny, the first appearance of contract both in Roman and German law has often been attributed to the case of a sale by some accident remaining incomplete. The question does not seem to be of great philosophical significance. For to explain how mankind first learned to promise, we must go to metaphysics, and find out how it ever came to frame a future tense. The nature of the particular promise which was first enforced in a given system can hardly lead to any truth of general importance. But the history of the action of debt is instructive, although in a humbler way. It is necessary to know something about it in order to understand the enlightened rules which make up the law of contract at the present time.

In Glanvill’s treatise the action of debt is found already to be one of the well-known remedies. But the law of those days was still in a somewhat primitive state, and it will easily be imagined that a form of action which goes back as far as that was not founded on any very delicate discriminations. It was, as I shall try to show directly, simply the general form in which any money claim was collected, except unliquidated claims for damages by force, for which there was established the equally general remedy of trespass.

It has been thought that the action was adopted from the then more civilized procedure of the Roman law. A natural opinion, seeing that all the early English law-writers adopt their phraseology and classification from Rome. Still it seems much more probable that the action is of pure German descent. It has the features of the primitive procedure which is found upon the Continent, as described by Laband. /1/

The substance of the plaintiff’s claim as set forth in the writ of debt is that the defendant owes him so much and wrongfully withholds it. It does not matter, for a claim framed like that, how the defendant’s duty arises. It is not confined to contract. It is satisfied if there is a duty to pay on any ground. It states a mere conclusion of law, not the facts upon which that conclusion is based, and from which the liability arises. The old German complaint was, in like manner, “A owes me so much.”

It was characteristic of the German procedure that the defendant could meet that complaint by answering, in an equally general form, that he did not owe the plaintiff. The plaintiff had to do more than simply allege a debt, if he would prevent the defendant from escaping in that way. In England, if the plaintiff had not something to show for his debt, the defendant’s denial turned him out of court; and even if he had, he was liable to be defeated by the defendant’s swearing with some of his friends to back him that he owed nothing. The chief reason why debt was supplanted for centuries by a later remedy, assumpsit, was the survival of this relic of early days.

Finally, in England as in Germany, debt for the detention of money was the twin brother of the action brought for wrongfully withholding any other kind of chattel. The gist of the complaint in either case was the same.

It seems strange that this crude product of the infancy of law should have any importance for us at the present time. Yet whenever we trace a leading doctrine of substantive law far enough back, we are very likely to find some forgotten circumstance of procedure at its source. Illustrations of this truth have been given already. The action of debt and the other actions of contract will furnish others. Debt throws most light upon the doctrine of consideration.

Our law does not enforce every promise which a man may make. Promises made as ninety-nine promises out of a hundred are, by word of mouth or simple writing, are not binding unless there is a consideration for them. That is, as it is commonly explained, unless the promisee has either conferred a benefit on the promisor, or incurred a detriment, as the inducement to the promise.

It has been thought that this rule was borrowed from Roman law by the Chancery, and, after undergoing some modification there, passed into the common law.

But this account of the matter is at least questionable. So far as the use of words goes, I am not aware that consideration is distinctly called cause before the reign of Elizabeth; in the earlier reports it always appears as quid pro quo. Its first appearance, so far as I know, is in Fleta’s account of the action of debt, /1/ and although I am inclined to believe that Fleta’s statement is not to be trusted, a careful consideration of the chronological order of the cases in the Year Books will show, I think, that the doctrine was fully developed in debt before any mention of it in equity can be found. One of the earliest references to what a promisor was to have for his undertaking was in the action of assumpsit. /1/ But the doctrine certainly did not originate there. The first mention of consideration in connection with equity which I have seen is in the form of quid pro quo, /2/ and occurs after the requirement had been thoroughly established in debt. /3/

The single fact that a consideration was never required for contracts under seal, unless Fleta is to be trusted against the great weight of nearly contemporaneous evidence, goes far to show that the rule cannot have originated on grounds of policy as a rule of substantive law. And conversely, the coincidence of the doctrine with a peculiar mode of procedure points very strongly to the probability that the peculiar requirement and the peculiar procedure were connected. It will throw light on the question to put together a few undisputed facts, and to consider what consequences naturally followed. It will therefore be desirable to examine the action of debt a little further. But it is only fair to admit, at the outset, that I offer the explanation which follows with great hesitation, and, I think, with a full appreciation of the objections which might be urged.

It was observed a moment ago, that, in order to recover against a defendant who denied his debt, the plaintiff had to show something for it; otherwise he was turned over to the limited jurisdiction of the spiritual tribunals. /4/ This requirement did not mean evidence in the modern sense. It meant simply that he must maintain his cause in one of the ways then recognized by law. These were three, the duel, a writing, and witnesses. The duel need not be discussed, as it soon ceased to be used in debt, and has no bearing on what I have to say. Trial by writing and by witnesses, on the other hand, must both be carefully studied. It will be convenient to consider the latter first and to find out what these witnesses were.

One thing we know at the start; they were not witnesses as we understand the term. They were not produced before a jury for examination and cross-examination, nor did their testimony depend for its effect on being believed by the court that heard it. Nowadays, a case is not decided by the evidence, but by a verdict, or a finding of facts, followed by a judgment. The oath of a witness has no effect unless it is believed. But in the time of Henry II. our trial by jury did not exist. When an oath was allowed to be sworn it had the same effect, whether it was believed or not. There was no provision for sifting it by a second body. In those cases where a trial by witnesses was possible, if the party called on to go forward could find a certain number of men who were willing to swear in a certain form, there was an end of the matter.

Now this seems like a more primitive way of establishing a debt than the production of the defendant’s written acknowledgement, and it is material to discover its origin.

The cases in which this mode of trial was used appear from the early books and reports to have been almost wholly confined to claims arising out of a sale or loan. And the question at once occurs, whether we are not upon traces of an institution which was already ancient when Glanvill wrote. For centuries before the Conquest Anglo-Saxon law /1/ had required the election of a certain number of official witnesses, two or three of whom were to be called in to every bargain of sale. The object for which these witnesses were established is not commonly supposed to have been the proof of debts. They go back to a time when theft and similar offences were the chief ground of litigation, and the purpose for which they were appointed was to afford a means of deciding whether a person charged with having stolen property had come by it rightfully or not. A defendant could clear himself of the felony by their oath that he had bought or received the thing openly in the way appointed by law.

Having been present at the bargain, the witnesses were able to swear to what they had seen and heard, if any question arose between the parties. Accordingly, their use was not confined to disposing of a charge of felony. But that particular service identifies the transaction witnesses of the Saxon period. Now we know that the use of these witnesses did not at once disappear under Norman influence. They are found with their old function in the laws of William the Conqueror. /1/ The language of Glanvill seems to prove that they were still known under Henry II. He says that, if a purchaser cannot summon in the man from whom he bought, to warrant the property to him and defend the suit, (for if he does, the peril is shifted to the seller,) then if the purchaser has sufficient proof of his having lawfully bought the thing, de legittimo marcatu suo, it will clear him of felony. But if he have not sufficient suit, he will be in danger. /2/ This is the law of William over again. It follows that purchasers still used the transaction witnesses.

But Glanvill also seems to admit the use of witness to establish debts. /1/ As the transaction witnesses were formerly available for this purpose, I see no reason to doubt that they still were, and that he is speaking of them here also. /2/ Moreover, for a long time after Henry II., whenever an action was brought for a debt of which there was no written evidence, the plaintiff, when asked what he had to show for it, always answered “good suit,” and tendered his witnesses, who were sometimes examined by the court. /3/ I think it is not straining the evidence to infer that the “good suit” of the later reports was the descendant of the Saxon transaction witnesses, as it has been shown that Glanvill’s secta was. /4/

Assuming this step in the argument to have been taken, it will be well to recall again for a moment the original nature of the witness oath. It was confined to facts within the witnesses’ knowledge by sight and hearing. But as the purposes for which witnesses were provided only required their presence when property changed hands, the principal case in which they could be of service between the parties to a bargain was when a debt was claimed by reason of the delivery of property. The purpose did not extend to agreements which were executory on both sides, because there no question of theft could arise. And Glanvill shows that in his time the King’s Court did not enforce such agreements. /1/ Now, if the oath of the secta could only be used to establish a debt where the transaction witnesses could have sworn, it will be seen, readily enough, how an accident of procedure may have led to a most important rule of substantive law.

The rule that witnesses could only swear to facts within their knowledge, coupled with the accident that these witnesses were not used in transactions which might create a debt, except for a particular fact, namely, the delivery of property, together with the further accident that this delivery was quid pro quo, was equivalent to the rule that, when a debt was proved by witnesses there must be quid pro quo. But these debts proved by witnesses, instead of by deed are what we call simple contract debts, and thus beginning with debt, and subsequently extending itself to other contracts, is established our peculiar and most important doctrine that every simple contract must have a consideration. This was never the law as to debts or contracts proved in the usual way by the defendant’s seal, and the fact that it applied only to obligations which were formerly established by a procedure of limited use, goes far to show that the connection with procedure was not accidental.

The mode of proof soon changed, but as late as the reign of Queen Elizabeth we find a trace of this original connection. It is said, “But the common law requires that there should be a new cause (i. e. consideration), whereof the country may have intelligence or knowledge for the trial of it, if need be, so that it is necessary for the Public-weal.” /1/ Lord Mansfield showed his intuition of the historical grounds of our law when he said, “I take it that the ancient notion about the want of consideration was for the sake of evidence only; for when it is reduced into writing, as in covenants, specialties, bonds, etc., there was no objection to the want of consideration.” /2/

If it should be objected that the preceding argument is necessarily confined to debt, whereas the requirement of consideration applies equally to all simple contracts, the answer is, that in all probability the rule originated with debt, and spread from debt to other contracts.

But, again, it may be asked whether there were no other contracts proved by witness except those which have been mentioned. Were there no contracts proved in that way to which the accidental consideration was wanting? To this also there is an easy answer. The contracts enforced by the civil courts, even as late as Henry II., were few and simple. The witness procedure was no doubt broad enough for all the contracts which were made in early times. Besides those of sale, loan, and the like, which have been mentioned, I find but two contractual obligations. These were the warranties accompanying a sale and suretyship which was referred to at the beginning of the Lecture. Of the former, warranty of title was rather regarded as an obligation raised by the law out of the relation of buyer and seller than as a contract. Other express warranties were matters within the knowledge of the transaction witnesses, and were sworn to by them in Saxon times. /1/

But in the Norman period warranty is very little heard of, except with regard to land, and then it was decided by the duel. It so wholly disappeared, except where it was embodied in a deed, that it can have had no influence upon the law of consideration. I shall therefore assume, without more detail, that it does not bear upon the case./1/

Then as to the pledge or surety. He no longer paid with his body, unless in very exceptional cases, but his liability was translated into money, and enforced in an action of debt. This time-honored contract, like the other debts of Glanvill’s time, could be established by witness without a writing, /2/ and in this case there was not such a consideration, such a benefit to the promisor, as the law required when the doctrine was first enunciated. But this also is unimportant, because his liability on the oath of witness came to an end, as well as that of the warrantor, before the foundations were laid for the rule which I am seeking to explain. A writing soon came to be required, as will be seen in a moment.

The result so far is, that the only action of contract in Glanvill’s time was debt, that the only debts recovered without writing were those which have been described, and that the only one of these for which there was not quid pro quo ceased to be recoverable in that way by the reign of Edward III.

But great changes were beginning in the reign of Henry II. More various and complex contracts soon came to be enforced. It may be asked, Why was not the scope of the witness oath enlarged, or, if any better proof were forthcoming, why was not the secta done away with, and other oral testimony admitted? In any event, what can the law of Henry II.’s time have to do with consideration, which not heard of until centuries later?

It is manifest that a witness oath, which disposes of a case by the simple fact that it is sworn, is not a satisfactory mode of proof. A written admission of debt produced in court, and sufficiently identified as issuing from the defendant, is obviously much better. The only weak point about a writing is the means of identifying it as the defendant’s, and this difficulty disappeared as soon as the use of seals became common. This had more or less taken place in Glanvill’s time, and then all that a party had to do was to produce the writing and satisfy the court by inspection that the impression on the wax fitted his opponent’s seal. /1/ The oath of the secta could always be successfully met by wager of law, /2/ that is, by a counter oath the part of the defendant, with the same or double the number of fellow-swearers produced by the plaintiff. But a writing proved to be the defendant’s could not be contradicted. /1/ For if a man said he was bound, he was bound. There was no question of consideration, because there was as yet no such doctrine. He was equally bound if he acknowledged all obligation in any place having a record, such as the superior courts, by which his acknowledgment could be proved. Indeed, to this day some securities are taken simply by an oral admission before the clerk of a court noted by him in his papers. The advantage of the writing was not only that it furnished better proof in the old cases, but also that it made it possible to enforce obligations for which there would otherwise have been no proof at all.

What has been said sufficiently explains the preference of proof by writing to proof by the old-fashioned witness oath. But there were other equally good reasons why the latter should not be extended beyond its ancient limits. The transaction witnesses were losing their statutory and official character. Already in Glanvill’s time the usual modes of proving a debt were by the duel or by writing. /2/ A hundred years later Bracton shows that the secta had degenerated to the retainers and household of the party, and he says that their oath raises but a slight presumption. /3/

Moreover, a new mode of trial was growing up, which, although it was not made use of in these cases /4/ for a good while, must have tended to diminish the estimate set on the witness oath by contrast. This was the beginning of our trial by jury. It was at first an inquest of the neighbors most likely to know about a disputed matter of fact. They spoke from their own knowledge, but they were selected by an officer of the court instead of by the interested party, and were intended to be impartial. /1/ Soon witnesses were summoned before them, not, as of old, to the case by their oath, but to aid the inquest to find a verdict by their testimony. With the advent of this enlightened procedure, the secta soon ceased to decide the case, and it may well be asked why it did not disappear and leave no traces.

Taking into account the conservatism of the English law, and the fact that, before deeds came in, the only debts for which there had been a remedy were debts proved by the transaction witnesses, it would not have been a surprise to find the tender of suit persisting in those cases. But there was another reason still more imperative. The defence in debt where there was no deed was by wager of law. /2/ A section of Magna Charta was interpreted to prohibit a man’s being put to his law on the plaintiff’s own statement without good witness. /3/ Hence, the statute required witness—that is, the secta—in every case of debt where the plaintiff did not rely upon a writing. Thus it happened that suit continued to be tendered in those cases where it had been of old, /4/ and as the defendant, if he did not admit the debt in such cases, always waged his law, it was long before the inquest got much foothold.

To establish a debt which arose merely by way of promise or acknowledgment, and for which there had formerly been no mode of trial provided, you must have a writing, the new form of proof which introduced it into the law. The rule was laid down, “by parol the party is not obliged.” /1/ But the old debts were not conceived of as raised by a promise. /2/ They were a “duty” springing from the plaintiff’s receipt of property, a fact which could be seen and sworn to. In these cases the old law maintained and even extended itself a little by strict analogy.

But the undertaking of a surety, in whatever form it was clothed, did not really arise out of any such fact. It had become of the same nature as other promises, and it was soon doubted whether it should not be proved by the same evidence. /3/ By the reign of Edward III., it was settled that a deed was necessary, /4/ except where the customs of particular cities had kept the old law in force. /5/

This reign may be taken as representing the time when the divisions and rules of procedure were established which have lasted until the present day. It is therefore worth while to repeat and sum up the condition of the law at that time.

It was still necessary that the secta should be tendered in every action of debt for which no writing was produced. For this, as well as for the other reasons which have been mentioned, the sphere of such actions was not materially enlarged beyond those cases which had formerly been established by the witness-oath. As suretyship was no longer one of these, they became strictly limited to cases in which the debt arose from the receipt of a quid pro quo. Moreover there was no other action of contract which could be maintained without a writing. New species of contracts were now enforced by an action of covenant, but there a deed was always necessary. At the same time the secta had shrunk to a form, although it was still argued that its function was more important in contract than elsewhere. It could no longer be examined before the court. /1/ It was a mere survival, and the transaction witness had ceased to be an institution. Hence, the necessity of tendering the witness oath did not fix the limit of debt upon simple contract except by tradition, and it is not surprising to find that the action was slightly extended by analogy from its scope in Glanvill’s time.

But debt remained substantially at the point which I have indicated, and no new action available for simple contracts was introduced for a century. In the mean time the inversion which I have explained took place, and what was an accident of procedure had become a doctrine of substantive law. The change was easy when the debts which could be enforced without deed all sprung from a benefit to the debtor.

The influence of the Roman law, no doubt, aided in bringing about this result. It will be remembered that in the reign of Henry II. most simple contracts and debts for which there was not the evidence of deed or witness were left to be enforced by the ecclesiastical courts, so far as their jurisdiction extended. /2/ Perhaps it was this circumstance which led Glanvill and his successors to apply the terminology of the civilians to common-law debts. But whether he borrowed it from the ecclesiastical courts, or went directly to the fountain-head, certain it is that Glanvill makes use of the classification and technical language of the Corpus Juris throughout his tenth book.

There were certain special contracts in the Roman system called real, which bound the contractor either to return a certain thing put into his hands by the contractee, as in a case of lease or loan, or to deliver other articles of the same kind, as when grain, oil, or money was lent. This class did not correspond, except in the most superficial way, with the common-law debts. But Glanvill adopted the nomenclature, and later writers began to draw conclusions from it. The author of Fleta, a writer by no means always intelligent in following and adopting his predecessors’ use of the Roman law, /1/ says that to raise a debt there must be not only a certain thing promised, but a certain thing promised in return. /2/

If Fleta had confined his statement to debts by simple contract, it might well have been suggested by the existing state of the law. But as he also required a writing and a seal, in addition to the matter given or promised in return, the doctrine laid down by him can hardly have prevailed at any time. It was probably nothing more than a slight vagary of reasoning based upon the Roman elements which he borrowed from Bracton.

It only remains to trace the gradual appearance of consideration in the decisions. A case of the reign of Edward III. /1/ seems to distinguish between a parol obligation founded on voluntary payments by the obligee and one founded on a payment at the obligor’s request. It also speaks of the debt or “duty” in that case as arising by cause of payments. Somewhat similar language is used in the next reign. /2/ So, in the twelfth year of Henry IV., /3/ there is an approach to the thought: “If money is promised to a man for making a release, and he makes the release, he will have a good action of debt in the matter.” In the next reign /4/ it was decided that, in such a case, the plaintiff could not recover without having executed the release, which is explained by the editor on the ground that ex nudo pacto non oritur actio. But the most important fact is, that from Edward I. to Henry VI. we find no case where a debt was recovered, unless a consideration had in fact been received.

Another fact to be noticed is, that since Edward III. debts arising from a transaction without writing are said to arise from contract, as distinguished from debts arising from an obligation. /5/ Hence, when consideration was required as such, it was required in contracts not under seal, whether debts or not. Under Henry VI. quid pro quo became a necessity in all such contracts. In the third year of that reign /6/ it was objected to au action upon an assumpsit for not building a mill, that it was not shown what the defendant was to have for doing it. In the thirty-sixth year of the same reign (A.D. 1459), the doctrine appears full grown, and is assumed to be familiar. /1/

The case turned upon a question which was debated for centuries before it was settled, whether debt would lie for a sum of money promised by the defendant to the plaintiff if he would marry the defendant’s daughter. But whereas formerly the debate had been whether the promise was not so far incident to the marriage that it belonged exclusively to the jurisdiction of the spiritual courts, it now touched the purely mundane doubt whether the defendant had had quid pro quo.

It will be remembered that the fact formerly sworn to by the transaction witnesses was a benefit to the defendant, namely, a delivery of the things sold or the money lent to him. Such cases, also, offer the most obvious form of consideration. The natural question is, what the promisor was to have for his promise. /2/ It is only by analysis that the supposed policy of the law is seen to be equally satisfied by a detriment incurred by the promisee. It therefore not unnaturally happened that the judges, when they first laid down the law that there must be quid pro quo, were slow to recognize a detriment to the contractee as satisfying the requirement which had been laid down. In the case which I have mentioned some of the judges were inclined to hold that getting rid of his daughter was a sufficient benefit to the defendant to make him a debtor for the money which he promised; and there was even some hint of the opinion, that marrying the lady was a consideration, because it was a detriment to the promisee. /1/ But the other opinion prevailed, at least for a time, because the defendant had had nothing from the plaintiff to raise a debt. /2/

So it was held that a service rendered to a third person upon the defendant’s request and promise of a reward would not be enough, /3/ although not without strong opinions to the contrary, and for a time the precedents were settled. It became established law that an action of debt would only lie upon a consideration actually received by and enuring to the benefit of the debtor.

It was, however, no peculiarity of either the action or contract of debt which led to this view, but the imperfectly developed theory of consideration prevailing between the reigns of Henry VI. and Elizabeth. The theory the same in assumpsit, /4/ and in equity. /5/ Wherever consideration was mentioned, it was always as quid pro quo, as what the contractor was to have for his contract.

Moreover, before consideration was ever heard of, debt was the time-honored remedy on every obligation to pay money enforced by law, except the liability to damages for a wrong. /6/ It has been shown already that a surety could be sued in debt until the time of Edward III. without a writing, yet a surety receives no benefit from the dealing with his principal. For instance, if a man sells corn to A, and B says, “I will pay if A does not,” the sale does B no good so far as appears by the terms of the bargain. For this reason, debt cannot now be maintained against a surety in such a case.

It was not always so. It is not so to this day if there is an obligation under seal. In that case, it does not matter how the obligation arose, or whether there was any consideration for it or not. But a writing was a more general way of establishing a debt in Glanvill’s time than witness, and it is absurd to determine the scope of the action by considering only a single class of debts enforced by it. Moreover, a writing for a long time was only another, although more conclusive, mode of proof. The foundation of the action was the same, however it was proved. This was a duty or “duity” /1/ to the plaintiff, in other words, that money was due him, no matter how, as any one may see by reading the earlier Year Books. Hence it was, that debt lay equally upon a judgment, /2/ which established such a duty by matter of record, or upon the defendant’s admission recorded in like manner. /3/

To sum up, the action of debt has passed through three stages. At first, it was the only remedy to recover money due, except when the liability was simply to pay damages for a wrongful act. It was closely akin to—indeed it was but a branch of—the action for any form of personal property which the defendant was bound by contract or otherwise to hand over to the plaintiff. /4/ If there was a contract to pay money, the only question was how you could prove it. Any such contract, which could be proved by any of the means known to early law, constituted a debt. There was no theory of consideration, and therefore, of course, no limit to either the action or the contract based upon the nature of the consideration received.

The second stage was when the doctrine of consideration was introduced in its earlier form of a benefit to the promisor. This applied to all contracts not under seal while it prevailed, but it was established while debt was the only action for money payable by such contracts. The precedents are, for the most part, precedents in debt.

The third stage was reached when a larger view was taken of consideration, and it was expressed in terms of detriment to the promisee. This change was a change in substantive law, and logically it should have been applied throughout. But it arose in another and later form of action, under circumstances peculiarly connected with that action, as will be explained hereafter. The result was that the new doctrine prevailed in the new action, and the old in the old, and that what was really the anomaly of inconsistent theories carried out side by side disguised itself in the form of a limitation upon the action of debt. That action did not remain, as formerly, the remedy for all binding contracts to pay money, but, so far as parol contracts were concerned, could only be used where the consideration was a benefit actually received by the promisor. With regard to obligations arising in any other way, it has remained unchanged.

I must now devote a few words to the effect upon our law of the other mode of proof which I have mentioned. I mean charters. A charter was simply a writing. As few could write, most people had to authenticate a document in some other way, for instance, by making their mark. This was, in fact, the universal practice in England until the introduction of Norman customs. /1/ With them seals came in. But as late as Henry II. they were said by the Chief Justice of England to belong properly only to kings and to very great men. /2/ I know no ground for thinking that an authentic charter had any less effect at that time when not under seal than when it was sealed. /3/ It was only evidence either way, and is called so in many of the early cases. /4/ It could be waived, and suit tendered in its place. /5/ Its conclusive effect was due to the satisfactory nature of the evidence, not to the seal. /6/

But when seals came into use they obviously made the evidence of the charter better, in so far as the seal was more difficult to forge than a stroke of the pen. Seals acquired such importance, that, for a time, a man was bound by his seal, although it was affixed without his consent. /7/ At last a seal came to be required, in order that a charter should have its ancient effect. /8/

A covenant or contract under seal was no longer a promise well proved; it was a promise of a distinct nature, for which a distinct form of action came to be provided. /1/ I have shown how the requirement of consideration became a rule of substantive law, and also why it never had any foothold in the domain of covenants. The exception of covenants from the requirement became a rule of substantive law also. The man who had set his hand to a charter, from being bound because he had consented to be, and because there was a writing to prove it, /2/ was now held by force of the seal and by deed alone as distinguished from all other writings. And to maintain the integrity of an inadequate theory, a seal was said to a consideration.

Nowadays, it is sometimes thought more philosophical to say that a covenant is a formal contract, which survives alongside of the ordinary consensual contract, just as happened in the Roman law. But this is not a very instructive way of putting it either. In one sense, everything is form which the law requires in order to make a promise binding over and above the mere expression of the promisor’s will. Consideration is a form as much as a seal. The only difference is, that one form is of modern introduction, and has a foundation in good sense, or at least in with our common habits of thought, so that we do not notice it, whereas the other is a survival from an older condition of the law, and is less manifestly sensible, or less familiar. I may add, that, under the influence of the latter consideration, the law of covenants is breaking down. In many States it is held that a mere scroll or flourish of the pen is a sufficient seal. From this it is a short step to abolish the distinction between sealed and unsealed instruments altogether, and this has been done in some of the Western States.

While covenants survive in a somewhat weak old age, and debt has disappeared, leaving a vaguely disturbing influence behind it, the whole modern law of contract has grown up through the medium of the action of Assumpsit, which must now be explained.

After the Norman conquest all ordinary actions were begun by a writ issuing from the king, and ordering the defendant to be summoned before the court to answer the plaintiff. These writs were issued as a matter of course, in the various well-known actions from which they took their names. There were writs of debt and of covenant; there were writs of trespass for forcible injuries to the plaintiff’s person, or to property in his possession, and so on. But these writs were only issued for the actions which were known to the law, and without a writ the court had no authority to try a case. In the time of Edward I. there were but few of such actions. The cases in which you could recover money of another fell into a small number of groups, for each of which there was a particular form of suing and stating your claim.

These forms had ceased to be adequate. Thus there were many cases which did not exactly fall within the definition of a trespass, but for which it was proper that a remedy should be furnished. In order to furnish a remedy, the first thing to be done was to furnish a writ. Accordingly, the famous statute of 13 Edward I., c. 24, authorized the office from which the old writs issued to frame new ones in cases similar in principle to those for which writs were found, and requiring like remedy, but not exactly falling within the scope of the writs already in use.

Thus writs of trespass on the case began to make their appearance; that is, writs stating a ground of complaint to a trespass, but not quite amounting to a trespass as it had been sued for in the older precedents. To take an instance which is substantially one of the earliest cases, suppose that a man left a horse with a blacksmith to be shod, and he negligently drove a nail into the horse’s foot. It might be that the owner of the horse could not have one of the old writs, because the horse was not in his possession when the damage was done. A strict trespass property could only be committed against the person in possession of it. It could not be committed by one who was in possession himself. /1/ But as laming the horse was equally a wrong, whether the owner held the horse by the bridle or left it with the smith, and as the wrong was closely analogous to a trespass, although not one, the law gave the owner a writ of trespass on the case. /2/

An example like this raises no difficulty; it is as much an action of tort for a wrong as trespass itself. No contract was stated, and none was necessary on principle. But this does not belong to the class of cases to be considered, for the problem before us is to trace the origin of assumpsit, which is an action of contract. Assumpsit, however, began as an action of trespass on the case, and the thing to be discovered is how trespass on the case ever became available for a mere breach of agreement.

It will be well to examine some of the earliest cases in which an undertaking (assumpsit) was alleged. The first reported in the books is of the reign of Edward III. /3/ The plaintiff alleged that the defendant undertook to carry the plaintiff’s horse safely across the Humber, but surcharged the boat, by reason of which the horse perished. It was objected that the action should have been either covenant for breach of the agreement, or else trespass. But it was answered that the defendant committed a wrongful act when he surcharged the boat, and the objection was overruled. This case again, although an undertaking was stated, hardly introduced a new principle. The force did not proceed directly from the defendant, to be sure, but it was brought to bear by the combination of his overloading and then pushing into the stream.

The next case is of the same reign, and goes further. /1/ The writ set forth that the defendant undertook to cure the plaintiff’s horse of sickness (manucepit equum praedicti W. de infirmirate), and did his work so negligently that the horse died. This differs from the case of laming the horse with a nail in two respects. It does not charge any forcible act, nor indeed any act at all, but a mere omission. On the other hand, it states an undertaking, which the other did not. The defendant at once objected that this was an action for a breach of an undertaking, and that the plaintiff should have brought covenant. The plaintiff replied, that he could not do that without a deed, and that the action was for negligently causing the death of the horse; that is, for a tort, not for a breach of contract. Then, said the defendant, you might have had trespass. But the plaintiff answered that by saying that the horse was not killed by force, but died per def. de sa cure; and upon this argument the writ was adjudged good, Thorpe, J. saying that he had seen a man indicted for killing a patient by want of care (default in curing), whom he had undertaken to cure.

Both these cases, it will be seen, were dealt with by the court as pure actions of tort, notwithstanding the allegation of an undertaking on the part of the defendant. But it will also be seen that they are successively more remote from an ordinary case of trespass. In the case last stated, especially, the destroying force did not proceed from the defendant in any sense. And thus we are confronted with the question, What possible analogy could have been found between a wrongful act producing harm, and a failure to act at all?

I attempt to answer it, let me illustrate a little further by examples of somewhat later date. Suppose a man undertook to work upon another’s house, and by his unskilfulness spoiled his employer’s timbers; it would be like a trespass, although not one, and the employer would sue in trespass on the case. This was stated as clear law by one of the judges in the reign of Henry IV. /1/ But suppose that, instead of directly spoiling the materials, the carpenter had simply left a hole in the roof through which the rain had come in and done the damage. The analogy to the previous case is marked, but we are a step farther away from trespass, because the force does not come from the defendant. Yet in this instance also the judges thought that trespass on the case would lie. /2/ In the time of Henry IV. the action could not have been maintained for a simple refusal to build according to agreement; but it was suggested by the court, that, if the writ had mentioned “that the thing had been commenced and then by not done, it would have been otherwise.” /3/

I now recur to the question, What likeness could there have been between an omission and a trespass sufficient to warrant a writ of trespass on the case? In order to find an answer it is essential to notice that in all the earlier cases the omission occurred in the course of dealing with the plaintiff’s person or property, and occasioned damage to the one or the other. In view of this fact, Thorpe’s reference to indictments for killing a patient by want of care, and the later distinction between neglect before and after the task is commenced, are most pregnant. The former becomes still more suggestive when it is remembered that this is the first argument or analogy to be found upon the subject.

The meaning of that analogy is plain. Although a man has a perfect right to stand by and see his neighbor’s property destroyed, or, for the matter of that, to watch his neighbor perish for want of his help, yet if he once intermeddles he has no longer the same freedom. He cannot withdraw at will. To give a more specific example, if a surgeon from benevolence cuts the umbilical cord of a newly-born child, he cannot stop there and watch the patient bleed to death. It would be murder wilfully to allow death to come to pass in that way, as much as if the intention had been entertained at the time of cutting the cord. It would not matter whether the wickedness began with the act, or with the subsequent omission.

The same reasoning applies to civil liability. A carpenter need not go to work upon another man’s house at all, but if he accepts the other’s confidence and intermeddles, he cannot stop at will and leave the roof open to the weather. So in the case of the farrier, when he had taken charge of the horse, he could not stop at the critical moment and leave the consequences to fortune. So, still more clearly, when the ferryman undertook to carry a horse across the Humber, although the water drowned the horse, his remote acts of overloading his boat and pushing it into the stream in that condition occasioned the loss, and he was answerable for it.

In the foregoing cases the duty was independent of contract, or at least was so regarded by the judges who decided them, and stood on the general rules applied to human conduct even by the criminal law. The immediate occasion of the damage complained of may have been a mere omission letting in the operation of natural forces. But if you connect it, as it was connected in fact, with the previous dealings, you have a course of action and conduct which, taken as a whole, has caused or occasioned the harm.

The objection may be urged, to be sure, that there is a considerable step from holding a man liable for the consequences of his acts which he might have prevented, to making him answerable for not having interfered with the course of nature when he neither set it in motion nor opened the door for it to do harm, and that there is just that difference between making a hole in a roof and leaving it open, or cutting the cord and letting it bleed, on the one side, and the case of a farrier who receives a sick horse and omits proper precautions, on the other. /1/

There seem to be two answers to this. First, it is not clear that such a distinction was adverted to by the court which decided the case which I have mentioned. It was alleged that the defendant performed his cure so negligently that the horse died. It might not have occurred to the judges that the defendant’s conduct possibly went no further than the omission of a series of beneficial measures. It was probably assumed to have consisted of a combination of acts and neglects, which taken as a whole amounted to an improper dealing with the thing.

In the next place, it is doubtful whether the distinction is a sound one on practical grounds. It may well be that, so long as one allows a trust to be reposed in him, he is bound to use such precautions as are known to him, although he has made no contract, and is at liberty to renounce the trust in any reasonable manner. This view derives some support from the issue on which the parties went to trial, which was that the defendant performed the cure as well as he knew how, without this, that the horse died for default of his care (cure?). /1/

But it cannot be denied that the allegation of an undertaking conveyed the idea of a promise, as well as that of an entering upon the business in hand. Indeed, the latter element is sufficiently conveyed, perhaps, without it. It may be asked, therefore, whether the promise did not count for something in raising a duty to act. So far as this involves the consequence that the action was in fact for the breach of a contract, the answer has been given already, and is sustained by too great a weight of authority to be doubted. /2/ To bind the defendant by a contract, an instrument under seal was essential. As has been shown, already, even the ancient sphere of debt had been limited by this requirement, and in the time of Edward III. a deed was necessary even to bind a surety. It was so a fortiori to introduce a liability upon promises not enforced by the ancient law. Nevertheless, the suggestion was made at an early date, that an action on the case for damage by negligence, that is, by an omission of proper precautions, alleging an undertaking by way of inducement, was in fact an action of contract.

Five years after the action for negligence in curing a horse, which has been stated, an action was brought /1/ in form against a surgeon, alleging that he undertook to cure the plaintiff’s hand, and that by his negligence the hand was maimed. There was, however, this difference, that it was set forth that the plaintiff’s hand had been wounded by one T.B. And hence it appeared that, however much the bad treatment may have aggravated matters, the maiming was properly attributable to T.B., and that the plaintiff had an action against him. This may have led the defendant to adopt the course he did, because he felt uncertain whether any action of tort would lie. He took issue on the undertaking, assuming that to be essential to the plaintiff’s case, and then objected that the writ did not show the place of the undertaking, and hence was bad, because it did not show whence the inquest should be summoned to speak to that point. The writ was adjudged bad on that ground, which seems as if the court sanctioned the defendant’s view. Indeed, one of the judges called it an action of covenant, and said that “of necessity it was maintainable without specialty, because for so small a matter a man cannot always have a clerk at hand to write a deed” (pur faire especially). At the same time the earlier cases which [282] have been mentioned were cited and relied on, and it is evident that the court was not prepared to go beyond them, or to hold that the action could be maintained on its merits apart from the technical objection. In another connection it seems to have considered the action from the point of view of trespass. /1/

Whatever questions this case may suggest, the class of actions which alleged an undertaking on the part of the defendant continued to be dealt with as actions of tort for a long time after Edward III. The liability was limited to damage to person or property arising after the defendant had entered upon the employment. And it was mainly through reasoning drawn from the law of tort that it was afterwards extended, as will be seen.

At the beginning of the reign of Henry VI. it was probably still the law that the action would not lie for a simple failure to keep a promise. /2/ But it had been several times suggested, as has been shown, that it would be otherwise if the omission or neglect occurred in the course of performance, and the defendant’s conduct had been followed by physical damage. /3/ This suggestion took its most striking form in the early years of Henry VI., when the case of the carpenter leaving a hole in the roof was put. /4/ When the courts had got as far as this, it was easy to go one step farther, and to allow the same effect to an omission at any stage, followed by similar damage.

What is the difference in principle, it was asked, a few years later, /1/ between the cases where it is admitted that the action will lie, and that of a smith who undertakes to shoe a horse and does not, by reason of which the horse goes lame,—or that of a lawyer, who undertakes to argue your case, and, after thus inducing you to rely upon him, neglects to be present, so that you lose it? It was said that in the earlier instances the duty was dependent on or accessory to the covenant, and that, if the action would lie on the accessory matter, it would lie on the principal. /2/ It was held on demurrer that an action would lie for not procuring certain releases which the defendant had undertaken to get.

Five years later another case /3/ came up, which was very like that of the farrier in the reign of Edward III. It was alleged that the defendant undertook to cure the plaintiff’s horse, and applied medicine so negligently that the horse died. In this, as in the earlier case, the issue was taken on the assumpsit. And now the difference between an omission and an act was clearly stated, the declaration was held not to mean necessarily anything more than an omission, and it was said that but for the undertaking the defendant would have owed no duty to act. Hence the allegation of the defendant’s promise was material, and an issue could properly be taken on it.

This decision distinctly separated from the mass of actions on the case a special class arising out of a promise as the source of the defendant’s obligation, and it was only a matter of time for that class to become a new and distinct action of contract. Had this change taken place at once, the doctrine of consideration, which was first definitely enunciated about the same time, would no doubt have been applied, and a quid pro quo would have been required for the undertaking. /1/ But the notion of tort was not at once abandoned. The law was laid down at the beginning of the reign of Henry VII., in accordance with the earlier decisions, and it was said that the action would not lie for a failure to keep a promise, but only for negligence after the defendant had entered upon his undertaking. /2/

So far as the action did not exceed the true limits of tort, it was immaterial whether there was a consideration for the undertaking or not. But when the mistake was made of supposing that all cases, whether proper torts or not, in which an assumpsit was alleged, were equally founded on the promise, one of two erroneous conclusions was naturally thought to follow. Either no assumpsit needed any quid pro quo, /3/ as there was clearly none in the older precedents, (they being cases of pure tort,) or else those precedents were wrong, and a quid pro quo should be alleged in every case. It was long recognized with more or less understanding of the true limit, that, in cases where the gist of the action was negligent damage to property, a consideration was not necessary. /4/ And there are some traces of the notion that it was always superfluous, as late as Charles I.

In a case of that reign, the defendant retained an attorney to act in a suit for a third person, and promised to pay him all his fees and expenses. The attorney rendered the service, and then brought debt. It was objected that debt did not lie, because there was no contract between the parties, and the defendant had not any quid pro quo. The court adopted the argument, and said that there was no contract or consideration to ground this action, but that the plaintiff might have sued in assumpsit. /1/

It was, perhaps, the lingering of this idea, and the often repeated notion that an assumpsit was not a contract, /2/ to which was attributable a more enlarged theory of consideration than prevailed in debt. It was settled that assumpsit would lie for a mere omission or nonfeasance. The cases which have been mentioned of the reign of Henry VI. were followed by others in the latter years of Henry VII., /3/ and it was never again doubted. An action for such a cause was clearly for a breach of promise, as had been recognized from the time of Edward III. If so, a consideration was necessary. /4/ Notwithstanding occasional vagaries, that also had been settled or taken for granted in many cases of Queen Elizabeth’s time. But the bastard origin of the action which gave rise to the doubt how far any consideration at all was necessary, made it possible to hold considerations sufficient which had been in debt.

Another circumstance may not have been without its influence. It would seem that, in the period when assumpsit [286] was just growing into its full proportions, there was some little inclination to identify consideration with the Roman causa, taken in its broadest sense. The word “cause” was used for consideration in the early years of Elizabeth, with reference to a covenant to stand seized to uses. /1/ It was used in the same sense in the action of assumpsit. /2/ In the last cited report, although the principal case only laid down a doctrine that would be followed to-day, there was also stated an anonymous case which was interpreted to mean that an executed consideration furnished upon request, but without any promise of any kind, would support a subsequent promise to pay for it. /3/ Starting from this authority and the word “cause,” the conclusion was soon reached that there was a great difference between a contract and an assumpsit; and that, whereas in contracts “everything which is requisite ought to concur and meet together, viz. the consideration of the one side, and the sale or the promise on the other side,… to maintain an action upon an assumpsit, the same is not requisite, for it is sufficient if there be a moving cause or consideration precedent; for which cause or consideration the promise was made.” /4/

Thus, where the defendant retained the plaintiff to be to his aunt at ten shillings a week, it was held that assumpsit would lie, because the service, though not beneficial to the defendant, was a charge or detriment to the plaintiff. /1/ The old questions were reargued, and views which were very near prevailing in debt under Henry VI., prevailed in assumpsit under Elizabeth and James.

A surety could be sued in assumpsit, although he had ceased to be liable in debt. /2/ There was the same remedy on a promise in consideration that the plaintiff would marry the defendant’s daughter. /3/ The illusion that assumpsit thus extended did not mean contract, could not be kept up. In view of this admission and of the ancient precedents, the law oscillated for a time in the direction of reward as the true essence of consideration. /4/ But the other view prevailed, and thus, in fact, made a change in the substantive law. A simple contract, to be recognized as binding by the courts of Henry VI., must have been based upon a benefit to the debtor; now a promise might be enforced in consideration of a detriment to the promisee. But in the true archaic spirit the doctrine was not separated or distinguished from the remedy which introduced it, and thus debt in modern times has presented the altered appearance of a duty limited to cases where the consideration was of a special sort.

The later fortunes of assumpsit can be briefly told. It introduced bilateral contracts, because a promise was a detriment, and therefore a sufficient consideration for another promise. It supplanted debt, because the existence of the duty to pay was sufficient consideration for a promise to pay, or rather because, before a consideration was required, and as soon as assumpsit would lie for a nonfeasance, this action was used to avoid the defendant’s wager of law. It vastly extended the number of actionable contracts, which had formerly been confined to debts and covenants, whereas nearly any promise could be sued in assumpsit; and it introduced a theory which has had great influence on modern law,—that all the liabilities of a bailee are founded on contract. /1/ Whether the prominence which was thus given to contract as the foundation of legal rights and duties had anything to do with the similar prominence which it soon acquired in political speculation, it is beyond my province to inquire.




By Oliver Wendell Holmes, Jr.


The next subjects to be considered are fraud, malice, and intent. In the discussion of unintentional wrongs, the greatest difficulty to be overcome was found to be the doctrine that a man acts always at his peril. In what follows, on the other hand, the difficulty will be to prove that actual wickedness of the kind described by the several words just mentioned is not an element in the civil wrongs to which those words are applied.

It has been shown, in dealing with the criminal law, that, when we call an act malicious in common speech, we mean that harm to another person was intended to come of it, and that such harm was desired for its own sake as an end in itself. For the purposes of the criminal law, however, intent alone was found to be important, and to have the same consequences as intent with malevolence superadded. Pursuing the analysis, intent was found to be made up of foresight of the harm as a consequence, coupled with a desire to bring it about, the latter being conceived as the motive for the act in question. Of these, again, foresight only seemed material. As a last step, foresight was reduced to its lowest term, and it was concluded that, subject to exceptions which were explained, the general basis of criminal liability was knowledge, at the time of action of facts from which common experience showed that certain harmful results were likely to follow.

It remains to be seen whether a similar reduction is possible on the civil side of the law, and whether thus fraudulent, malicious, intentional, and negligent wrongs can be brought into a philosophically continuous series.

A word of preliminary explanation will be useful. It has been shown in the Lecture just referred to that an act, although always importing intent, is per se indifferent to the law. It is a willed, and therefore an intended coordination of muscular contractions. But the intent necessarily imported by the act ends there. And all muscular motions or co-ordinations of them are harmless apart from concomitant circumstances, the presence of which is not necessarily implied by the act itself. To strike out with the fist is the same act, whether done in a desert or in a crowd.

The same considerations which have been urged to show that an act alone, by itself, does not and ought not to impose either civil or criminal liability, apply, at least frequently, to a series of acts, or to conduct, although the series shows a further co-ordination and a further intent. For instance, it is the same series of acts to utter a sentence falsely stating that a certain barrel contains No. 1 Mackerel, whether the sentence is uttered in the secrecy of the closet, or to another man in the course of a bargain. There is, to be sure, in either case, the further intent, beyond the co-ordination of muscles for a single sound, to allege that a certain barrel has certain contents,—an intent necessarily shown by the ordering of the words. But both the series of acts and the intent are per se indifferent. They are innocent when spoken in solitude, and are only a ground of liability when certain concomitant circumstances are shown.

The intent which is meant when spoken of as an element of legal liability is an intent directed toward the harm complained of, or at least toward harm. It is not necessary in every case to carry the analysis back to the simple muscular contractions out of which a course of conduct is made up. On the same principle that requires something more than an act followed by damage to make a man liable, we constantly find ourselves at liberty to assume a co-ordinated series of acts as a proximately simple element, per se indifferent, in considering what further circumstances or facts must be present before the conduct in question is at the actor’s peril. It will save confusion and the need of repetition if this is borne in mind in the following discussion.

The chief forms of liability in which fraud, malice, and intent are said to be necessary elements, are deceit, slander and libel, malicious prosecution, and conspiracy, to which, perhaps, may be added trover.

Deceit is a notion drawn from the moral world, and in its popular sense distinctly imports wickedness. The doctrine of the common law with regard to it is generally stated in terms which are only consistent with actual guilt, and all actual guilty intent. It is said that a man is liable to an action for deceit if he makes a false representation to another, knowing it to be false, but intending that the other should believe and act upon it, if the person addressed believes it, and is thereby persuaded to act to his own harm. This is no doubt the typical case, and it is a case of intentional moral wrong. Now, what is the party’s conduct here. It consists in uttering certain words, so ordered that the utterance of them imports a knowledge of the meaning which they would convey if heard. But that conduct with only that knowledge is neither moral nor immoral. Go one step further, and add the knowledge of another’s presence within hearing, still the act has no determinate character. The elements which make it immoral are the knowledge that the statement is false, and the intent that it shall be acted on.

The principal question then is, whether this intent can be reduced to the same terms as it has been in other cases. There is no difficulty in the answer. It is perfectly clear that the intent that a false representation should be acted on would be conclusively established by proof that the defendant knew that the other party intended to act upon it. If the defendant foresaw the consequence of his acts, he is chargeable, whether his motive was a desire to induce the other party to act, or simply an unwillingness for private reasons to state the truth. If the defendant knew a present fact (the other party’s intent), which, according to common experience, made it likely that his act would have the harmful consequence, he is chargeable, whether he in fact foresaw the consequence or not.

In this matter the general conclusion follows from a single instance. For the moment it is admitted that in one case knowledge of a present fact, such as the other party’s intent to act on the false statement, dispenses with proof of an intent to induce him to act upon it, it is admitted that the lesser element is all that is necessary in the larger compound. For intent embraces knowledge sufficing for foresight, as has been shown. Hence, when you prove intent you prove knowledge, and intent may often be the easier to prove of the two. But when you prove knowledge you do not prove intent.

It may be said, however, that intent is implied or presumed in such a case as has been supposed. But this is only helping out a false theory by a fiction. It is very much like saying that a consideration is presumed for an instrument under seal; which is merely a way of reconciling the formal theory that all contracts must have a consideration with the manifest fact that sealed instruments do not require one. Whenever it is said that a certain thing is essential to liability, but that it is conclusively presumed from something else, there is always ground for suspicion that the essential clement is to be found in that something else, and not in what is said to be presumed from it.

With regard to the intent necessary to deceit, we need not stop with the single instance which has been given. The law goes no farther than to require proof either of the intent, or that the other party was justified in inferring such intention. So that the whole meaning of the requirement is, that the natural and manifest tendency of the representation, under the known circumstances, must have been to induce the opinion that it was made with a view to action, and so to induce action on the faith of it. The standard of what is called intent is thus really an external standard of conduct under the known circumstances, and the analysis of the criminal law holds good here.

Nor is this all. The law pursuing its course of specification, as explained in the last Lecture, decides what is the tendency of representations in certain cases,—as, for instance, that a horse is sound at the time of making a sale; or, in general, of any statement of fact which it is known the other party intends to rely on. Beyond these scientific rules lies the vague realm of the jury.

The other moral element in deceit is knowledge that the statement was false. With this I am not strictly concerned, because all that is necessary is accomplished when the elements of risk are reduced to action and knowledge. But it will aid in the general object of showing that the tendency of the law everywhere is to transcend moral and reach external standards, if this knowledge of falsehood can be transmuted into a formula not necessarily importing guilt, although, of course, generally accompanied by it in fact. The moment we look critically at it, we find the moral side shade away.

The question is, what known circumstances are enough throw the risk of a statement upon him who makes it, if it induces another man to act, and it turns out untrue. Now, it is evident that a man may take the risk of his statement by express agreement, or by an implied one which the law reads into his bargain. He may in legal language warrant the truth of it, and if it is not true, the law treats it as a fraud, just as much when he makes it fully believing it, as when he knows that it is untrue, and means to deceive. If, in selling a horse, the seller warranted him to be only five years old, and in fact he was thirteen, the seller could be sued for a deceit at common law, although he thought the horse was only five. /1/ The common-law liability for the truth of statements is, therefore, more extensive than the sphere of actual moral fraud. But, again, it is enough in general if a representation is made recklessly, without knowing whether it is true or false. Now what does “recklessly” mean. It does not mean actual personal indifference to the truth of the statement. It means only that the data for the statement were so far insufficient that a prudent man could not have made it without leading to the inference that he was indifferent. That is to say, repeating an analysis which has been gone through with before, it means that the law, applying a general objective standard, determines that, if a man makes his statement on those data, he is liable, whatever was the state of his mind, and although he individually may have been perfectly free from wickedness in making it.

Hence similar reasoning to that which has been applied already to intent may be applied to knowledge of falsity. Actual knowledge may often be easier to prove than that the evidence was insufficient to warrant the statement, and when proved it contains the lesser element. But as soon as the lesser element is shown to be enough, it is shown that the law is ready to apply an external or objective standard here also.

Courts of equity have laid down the doctrine in terms which are so wholly irrespective of the actual moral condition of the defendant as to go to an opposite extreme. It is said that “when a representation in a matter of business is made by one man to another calculated to induce him to adapt his conduct to it, it is perfectly immaterial whether the representation is made knowing it to be untrue, or whether it is made believing it to be true, if, in fact, it was untrue.” /1/

Perhaps the actual decisions could be reconciled on a narrower principle, but the rule just stated goes the length of saying that in business matters a man makes every statement (of a kind likely to be acted on) at his peril. This seems hardly justifiable in policy. The moral starting point of liability in general should never be forgotten, and the law cannot without disregarding it hold a man answerable for statements based on facts which would have convinced a wise and prudent man of their truth. The public advantage and necessity of freedom in imparting information, which privileges even the slander of a third person, ought a fortiori, it seems to me, to privilege statements made at the request of the party who complains of them.

The common law, at any rate, preserves the reference to morality by making fraud the ground on which it goes. It does not hold that a man always speaks at his peril. But starting from the moral ground, it works out an external standard of what would be fraudulent in the average prudent member of the community, and requires every member at his peril to avoid that. As in other cases, it is gradually accumulating precedents which decide that certain statements under certain circumstances are at the peril of the party who makes them.

The elements of deceit which throw the risk of his conduct upon a party are these. First, making a statement of facts purporting to be serious. Second, the known presence of another within hearing. Third, known facts sufficient to warrant the expectation or suggest the probability that the other party will act on the statement. (What facts are sufficient has been specifically determined by the courts in some instances; in others, no doubt, the question would go to the jury on the principles heretofore explained.) Fourth, the falsehood of the statement. This must be known, or else the known evidence concerning the matter of the statement must be such as would not warrant belief according to the ordinary course of human experience. (On this point also the court may be found to lay down specific rules in some cases. /1/)

I next take up the law of slander. It has often been said that malice is one of the elements of liability, and the doctrine is commonly stated in this way: that malice must exist, but that it is presumed by law from the mere speaking of the words; that again you may rebut this presumption of malice by showing that the words were spoken under circumstances which made the communication privileged,—as, for instance, by a lawyer in the necessary course of his argument, or by a person answering in good faith to inquiries as to the character of a former servant,— and then, it is said, the plaintiff may meet this defence in some cases by showing that the words were spoken with actual malice.

All this sounds as if at least actual intent to cause the damage complained of, if not malevolence, were at the bottom of this class of wrongs. Yet it is not so. For although the use of the phrase “malice” points as usual to an original moral standard, the rule that it is presumed upon proof of speaking certain words is equivalent to saying that the overt conduct of speaking those words may be actionable whether the consequence of damage to the plaintiff was intended or not. And this fails in with the general theory, because the manifest tendency of slanderous words is to harm the person of whom they are spoken. Again, the real substance of the defence is not that the damage was not intended,—that would be no defence at all; but that, whether it was intended or not,—that is, even if the defendant foresaw it and foresaw it with pleasure,—the manifest facts and circumstances under which he said it were such that the law considered the damage to the plaintiff of less importance than the benefit of free speaking.

It is more difficult to apply the same analysis to the last stage of the process, but perhaps it is not impossible. It is said that the plaintiff may meet a case of privilege thus made out on the part of the defendant, by proving actual malice, that is, actual intent to cause the damage complained of. But how is this actual malice made out? It is by showing that the defendant knew the statement which he made was false, or that his untrue statements were grossly in excess of what the occasion required. Now is it not very evident that the law is looking to a wholly different matter from the defendant’s intent? The fact that the defendant foresaw and foresaw with pleasure the damage to the plaintiff, is of no more importance in this case than it would be where the communication was privileged. The question again is wholly a question of knowledge, or other external standard. And what makes even knowledge important? It is that the reason for which a man is allowed in the other instances to make false charges against his neighbors is wanting. It is for the public interest that people should be free to give the best information they can under certain circumstances without fear, but there is no public benefit in having lies told at any time; and when a charge is known to be false, or is in excess of what is required by the occasion, it is not necessary to make that charge in order to speak freely, and therefore it falls under the ordinary rule, that certain charges are made at the party’s peril in case they turn out to be false, whether evil consequences were intended or not. The defendant is liable, not because his intent was evil, but because he made false charges without excuse.

It will be seen that the peril of conduct here begins farther back than with deceit, as the tendency of slander is more universally harmful. There must be some concomitant circumstances. There must at least be a human being in existence whom the statement designates. There must be another human being within hearing who understands the statement, and the statement must be false. But it is arguable that the latter of these facts need not be known, as certainly the falsity of the charge need not be, and that a man must take the risk of even an idle statement being heard, unless he made it under known circumstances of privilege. It would be no great curtailment of freedom to deny a man immunity in attaching a charge of crime to the name of his neighbor, even when he supposes himself alone. But it does not seem clear that the law would go quite so far as that.

The next form of liability is comparatively insignificant. I mean the action for malicious prosecution. A man may recover damages against another for maliciously and without probable cause instituting a criminal, or, in some cases, a civil prosecution against him upon a false charge. The want of probable cause refers, of course, only to the state of the defendant’s knowledge, not to his intent. It means the absence of probable cause in the facts known to the defendant when he instituted the suit. But the standard applied to the defendant’s consciousness is external to it. The question is not whether he thought the facts to constitute probable cause, but whether the court thinks they did.

Then as to malice. The conduct of the defendant consists in instituting proceedings on a charge which is in fact false, and which has not prevailed. That is the root of the whole matter. If the charge was true, or if the plaintiff has been convicted, even though he may be able now to prove that he was wrongly convicted, the defendant is safe, however great his malice, and however little ground he had for his charge.

Suppose, however, that the charge is false, and does not prevail. It may readily be admitted that malice did originally mean a malevolent motive, an actual intent to harm the plaintiff by making a false charge. The legal remedy here, again, started from the moral basis, the occasion for it, no doubt, being similar to that which gave rise to the old law of conspiracy, that a man’s enemies would sometimes seek his destruction by setting the criminal law in motion against him. As it was punishable to combine for such a purpose, it was concluded, with some hesitation, that, when a single individual wickedly attempted the same thing, he should be liable on similar grounds. /1/ I must fully admit that there is weighty authority to the effect that malice in its ordinary sense is to this day a distinct fact to be proved and to be found by the jury.

But this view cannot be accepted without hesitation. It is admitted that, on the one side, the existence of probable cause, believed in, is a justification notwithstanding malice; /2/ that, on the other, “it is not enough to show that the case appeared sufficient to this particular party, but it must be sufficient to induce a sober, sensible and discreet person to act upon it, or it must fail as a justification for the proceeding upon general grounds.” /1/ On the one side, malice alone will not make a man liable for instituting a groundless prosecution; on the other, his justification will depend, not on his opinion of the facts, but on that of the court. When his actual moral condition is disregarded to this extent, it is a little hard to believe that the existence of an improper motive should be material. Yet that is what malice must mean in this case, if it means anything. /2/ For the evil effects of a successful indictment are of course intended by one who procures all other to be indicted. I cannot but think that a jury would be told that knowledge or belief that the charge was false at the time of making it was conclusive evidence of malice. And if so, on grounds which need not be repeated, malice is not the important thing, but the facts known to the defendant.

Nevertheless, as it is obviously treading on delicate ground to make it actionable to set the regular processes of the law in motion, it is, of course, entirely possible to say that the action shall be limited to those cases where the charge was preferred from improper motives, at least if the defendant thought that there was probable cause. Such a limitation would stand almost alone in the law of civil liability. But the nature of the wrong is peculiar, and, moreover, it is quite consistent with the theory of liability here advanced that it should be confined in any given instance to actual wrong-doing in a moral sense.

The only other cause of action in which the moral condition of the defendant’s consciousness might seem to be important is conspiracy. The old action going by that name was much like malicious prosecution, and no doubt was originally confined to cases where several persons had conspired to indict another from malevolent motives. But in the modern action on the case, where conspiracy is charged, the allegation as a rule only means that two or more persons were so far co-operating in their acts that the act of any one was the act of all. Generally speaking, the liability depends not on the co-operation or conspiring, but on the character of the acts done, supposing them all to be done by one man, or irrespective of the question whether they were done by one or several. There may be cases, to be sure, in which the result could not be accomplished, or the offence could not ordinarily be proved, without a combination of several; as, for instance, the removal of a teacher by a school board. The conspiracy would not affect the case except in a practical way, but the question would be raised whether, notwithstanding the right of the board to remove, proof that they were actuated by malevolence would not make a removal actionable. Policy, it might be said, forbids going behind their judgment, but actual evil motives coupled with the absence of grounds withdraw this protection, because policy, although it does not require them to take the risk of being right, does require that they should judge honestly on the merits. /1/

Other isolated instances like the last might, perhaps, be found in different parts of the law, in which actual malevolence would affect a man’s liability for his conduct. Again, in trover for the conversion of another’s chattel, where the dominion exercised over it was of a slight and ambiguous nature, it has been said that the taking must be “with the intent of exercising an ownership over the chattel inconsistent with the real owner’s right of possession.” /1/ But this seems to be no more than a faint shadow of the doctrine explained with regard to larceny, and does not require any further or special discussion. Trover is commonly understood to go, like larceny, on the plaintiff’s being deprived of his property, although in practice every possessor has the action, and, generally speaking, the shortest wrongful withholding of possession is a conversion.

Be the exceptions more or less numerous, the general purpose of the law of torts is to secure a man indemnity against certain forms of harm to person, reputation, or estate, at the hands of his neighbors, not because they are wrong, but because they are harms. The true explanation of the reference of liability to a moral standard, in the sense which has been explained, is not that it is for the purpose of improving men’s hearts, but that it is to give a man a fair chance to avoid doing the harm before he is held responsible for it. It is intended to reconcile the policy of letting accidents lie where they fall, and the reasonable freedom of others with the protection of the individual from injury.

But the law does not even seek to indemnify a man from all harms. An unrestricted enjoyment of all his possibilities would interfere with other equally important enjoyments on the part of his neighbors. There are certain things which the law allows a man to do, notwithstanding the fact that he foresees that harm to another will follow from them. He may charge a man with crime if the charge is true. He may establish himself in business where he foresees that of his competition will be to diminish the custom of another shopkeeper, perhaps to ruin him. He may a building which cuts another off from a beautiful prospect, or he may drain subterranean waters and thereby drain another’s well; and many other cases might be put.

As any of these things may be done with foresight of their evil consequences, it would seem that they might be done with intent, and even with malevolent intent, to produce them. The whole argument of this Lecture and the preceding tends to this conclusion. If the aim of liability is simply to prevent or indemnify from harm so far as is consistent with avoiding the extreme of making a man answer for accident, when the law permits the harm to be knowingly inflicted it would be a strong thing if the presence of malice made any difference in its decisions. That might happen, to be sure, without affecting the general views maintained here, but it is not to be expected, and the weight of authority is against it.

As the law, on the one hand, allows certain harms to be inflicted irrespective of the moral condition of him who inflicts them, so, at the other extreme, it may on grounds of policy throw the absolute risk of certain transactions on the person engaging in them, irrespective of blameworthiness in any sense. Instances of this sort have been mentioned in the last Lecture, /1/ and will be referred to again.

Most liabilities in tort lie between these two extremes, and are founded on the infliction of harm which the defendant had a reasonable opportunity to avoid at the time of the acts or omissions which were its proximate cause. Rut as fast as specific rules are worked out in place of the vague reference to the conduct of the average man, they range themselves alongside of other specific rules based on public policy, and the grounds from which they spring cease to be manifest. So that, as will be seen directly, rules which seem to lie outside of culpability in any sense have sometimes been referred to remote fault, while others which started from the general notion of negligence may with equal ease be referred to some extrinsic ground of policy.

Apart from the extremes just mentioned, it is now easy to see how the point at which a man’s conduct begins to be at his own peril is generally fixed. When the principle is understood on which that point is determined by the law of torts, we possess a common ground of classification, and a key to the whole subject, so far as tradition has not swerved the law from a consistent theory. It has been made pretty clear from what precedes, that I find that ground in knowledge of circumstances accompanying an act or conduct indifferent but for those circumstances.

But it is worth remarking, before that criterion is discussed, that a possible common ground is reached at the preceding step in the descent from malice through intent and foresight. Foresight is a possible common denominator of wrongs at the two extremes of malice and negligence. The purpose of the law is to prevent or secure a man indemnity from harm at the hands of his neighbors, so far as consistent with other considerations which have been mentioned, and excepting, of course, such harm as it permits to be intentionally inflicted. When a man foresees that harm will result from his conduct, the principle which exonerates him from accident no longer applies, and he is liable. But, as has been shown, he is bound to foresee whatever a prudent and intelligent man would have foreseen, and therefore he is liable for conduct from which such a man would have foreseen that harm was liable to follow.

Accordingly, it would be possible to state all cases of negligence in terms of imputed or presumed foresight. It would be possible even to press the presumption further, applying the very inaccurate maxim, that every man is presumed to intend the natural consequences of his own acts; and this mode of expression will, in fact, be found to have been occasionally used, /1/ more especially in the criminal law, where the notion of intent has a stronger foothold. /2/ The latter fiction is more remote and less philosophical than the former; but, after all, both are equally fictions. Negligence is not foresight, but precisely the want of it; and if foresight were presumed, the ground of the presumption, and therefore the essential element, would be the knowledge of facts which made foresight possible.

Taking knowledge, then, as the true starting-point, the next question is how to determine the circumstances necessary to be known in any given case in order to make a man liable for the consequences of his act. They must be such as would have led a prudent man to perceive danger, although not necessarily to foresee the specific harm. But this is a vague test. How is it decided what those circumstances are? The answer must be, by experience.

But there is one point which has been left ambiguous in the preceding Lecture and here, and which must be touched upon. It has been assumed that conduct which the man of ordinary intelligence would perceive to be dangerous under the circumstances, would be blameworthy if pursued by him. It might not be so, however. Suppose that, acting under the threats of twelve armed men, which put him in fear of his life, a man enters another’s close and takes a horse. In such a case, he actually contemplates and chooses harm to another as the consequence of his act. Yet the act is neither blameworthy nor punishable. But it might be actionable, and Rolle, C. J. ruled that it was so in Gilbert v. Stone. /1/ If this be law, it goes the full length of deciding that it is enough if the defendant has had a chance to avoid inflicting the harm complained of. And it may well be argued that, although he does wisely to ransom his life as he best may, there is no reason why he should be allowed to intentionally and permanently transfer his misfortunes to the shoulders of his neighbors.

It cannot be inferred, from the mere circumstance that certain conduct is made actionable, that therefore the law regards it as wrong, or seeks to prevent it. Under our mill acts a man has to pay for flowing his neighbor’s lands, in the same way that he has to pay in trover for converting his neighbor’s goods. Yet the law approves and encourages the flowing of lands for the erection of mills.

Moral predilections must not be allowed to influence our minds in settling legal distinctions. If we accept the test of the liability alone, how do we distinguish between trover and the mill acts? Or between conduct which is prohibited, and that which is merely taxed? The only distinction which I can see is in the difference of the collateral consequences attached to the two classes of conduct. In the one, the maxim in pari delicto potior est conditio defendentis, and the invalidity of contracts contemplating it, show that the conduct is outside the protection of the law. In the other, it is otherwise. /1/ This opinion is confirmed by the fact, that almost the only cases in which the distinction between prohibition and taxation comes up concern the application of these maxims.

But if this be true, liability to an action does not necessarily import wrong-doing. And this may be admitted without at all impairing the force of the argument in the foregoing Lecture, which only requires that people should not be made to pay for accidents which they could not have avoided.

It is doubtful, however, whether the ruling of Chief Justice Rolle would now be followed. The squib case, Scott v. Shepherd, and the language of some text-books, are more or less opposed to it. /2/ If the latter view is law, then an act must in general not only be dangerous, but one which would be blameworthy on the part of the average man, in order to make the actor liable. But, aside from such exceptional cases as Gilbert v. Stone, the two tests agree, and the difference need not be considered in what follows.

I therefore repeat, that experience is the test by which it is decided whether the degree of danger attending given conduct under certain known circumstances is sufficient to throw the risk upon the party pursuing it.

For instance, experience shows that a good many guns supposed to be unloaded go off and hurt people. The ordinarily intelligent and prudent member of the community would foresee the possibility of danger from pointing a gun which he had not inspected into a crowd, and pulling the trigger, although it was said to be unloaded. Hence, it may very properly be held that a man who does such a thing does it at his peril, and that, if damage ensues, he is answerable for it. The co-ordinated acts necessary to point a gun and pull a trigger, and the intent and knowledge shown by the co-ordination of those acts, are all consistent with entire blamelessness. They threaten harm to no one without further facts. But the one additional circumstance of a man in the line and within range of the piece makes the conduct manifestly dangerous to any one who knows the fact. There is no longer any need to refer to the prudent man, or general experience. The facts have taught their lesson, and have generated a concrete and external rule of liability. He who snaps a cap upon a gun pointed in the direction of another person, known by him to be present, is answerable for the consequences.

The question what a prudent man would do under given circumstances is then equivalent to the question what are the teachings of experience as to the dangerous character of this or that conduct under these or those circumstances; and as the teachings of experience are matters of fact, it is easy to see why the jury should be consulted with regard to them. They are, however, facts of a special and peculiar function. Their only bearing is on the question, what ought to have been done or omitted under the circumstances of the case, not on what was done. Their function is to suggest a rule of conduct.

Sometimes courts are induced to lay down rules by facts of a more specific nature; as that the legislature passed a certain statute, and that the case at bar is within the fair meaning of its words; or that the practice of a specially interested class, or of the public at large, has generated a rule of conduct outside the law which it is desirable that the courts should recognize and enforce. These are matters of fact, and have sometimes been pleaded as such. But as their only importance is, that, if believed, they will induce the judges to lay down a rule of conduct, or in other words a rule of law, suggested by them, their tendency in most instances is to disappear as fast as the rules suggested by them become settled. /1/ While the facts are uncertain, as they are still only motives for decision upon the law,—grounds for legislation, so to speak,—the judges may ascertain them in any way which satisfies their conscience. Thus, courts recognize the statutes of the jurisdiction judicially, although the laws of other jurisdictions, with doubtful wisdom, are left to the jury. /2/ They may take judicial cognizance of a custom of merchants. /3/ In former days, at least, they might inquire about it in pais after a demurrer. /4/ They may act on the statement of a special jury, as in the time of Lord Mansfield and his successors, or upon the finding of a common jury based on the testimony of witnesses, as is the practice to-day in this country. But many instances will be found the text-books which show that, when the facts are ascertained, they soon cease to be referred to, and give place to a rule of law.

The same transition is noticeable with regard to the teachings of experience. There are many cases, no doubt, in which the court would lean for aid upon a jury; but there are also many in which the teaching has been formulated in specific rules. These rules will be found to vary considerably with regard to the number of concomitant circumstances necessary to throw the peril of conduct otherwise indifferent on the actor. As the circumstances become more numerous and complex, the tendency to cut the knot with the jury becomes greater. It will be useful to follow a line of cases up from the simple to the more complicated, by way of illustration. The difficulty of distinguishing rules based on other grounds of policy from those which have been worked out in the field of negligence, will be particularly noticed.

In all these cases it will be found that there has been a voluntary act on the part of the person to be charged. The reason for this requirement was shown in the foregoing Lecture. Unnecessary though it is for the defendant to have intended or foreseen the evil which he has caused, it is necessary that he should have chosen the conduct which led to it. But it has also been shown that a voluntary act is not enough, and that even a co-ordinated series of acts or conduct is often not enough by itself. But the co-ordination of a series of acts shows a further intent than is necessarily manifested by any single act, and sometimes proves with almost equal certainty the knowledge of one or more concomitant circumstances. And there are cases where conduct with only the intent and knowledge thus necessarily implied is sufficient to throw the risk of it on the actor.

For instance, when a man does the series of acts called walking, it is assumed for all purposes of responsibility that he knows the earth is under his feet. The conduct per se is indifferent, to be sure. A man may go through the motions of walking without legal peril, if he chooses to practise on a private treadmill; but if he goes through the same motions on the surface of the earth, it cannot be doubted that he knows that the earth is there. With that knowledge, he acts at his peril in certain respects. If he crosses his neighbor’s boundary, he is a trespasser. The reasons for this strict rule have been partially discussed in the last Lecture. Possibly there is more of history or of past or present notions of policy its explanation than is there suggested, and at any rate I do not care to justify the rule. But it is intelligible. A man who walks knows that he is moving over the surface of the earth, he knows that he is surrounded by private estates which he has no right to enter, and he knows that his motion, unless properly guided, will carry him into those estates. He is thus warned, and the burden of his conduct is thrown upon himself.

But the act of walking does not throw the peril of all possible consequences upon him. He may run a man down in the street, but he is not liable for that unless he does it negligently. Confused as the law is with cross-lights of tradition, and hard as we may find it to arrive at perfectly satisfactory general theory, it does distinguish in a pretty sensible way, according to the nature and degree of the different perils incident to a given situation.

From the simple case of walking we may proceed to the more complex cases of dealings with tangible objects of property. It may be said that, generally speaking, a man meddles with such things at his own risk. It does not matter how honestly he may believe that they belong to himself, or are free to the public, or that he has a license from the owner, or that the case is one in which the law has limited the rights of ownership; he takes the chance of how the fact may turn out, and if the fact is otherwise than as he supposes, he must answer for his conduct. As has been already suggested, he knows that he is exercising more or less dominion over property, or that he is injuring it; he must make good his right if it is challenged.

Whether this strict rule is based on the common grounds of liability, or upon some special consideration of past or present policy, policy has set some limits to it, as was mentioned in the foregoing Lecture.

Another case of conduct which is at the risk of the party without further knowledge than it necessarily imports, is the keeping of a tiger or bear, or other animal of a species commonly known to be ferocious. If such an animal escapes and does damage, the owner is liable simply on proof that he kept it. In this instance the comparative remoteness of the moment of choice in the line of causation from the effect complained of, will be particularly noticed. Ordinary cases of liability arise out of a choice which was the proximate cause of the harm upon which the action is founded. But here there is usually no question of negligence in guarding the beast. It is enough in most, if not in all cases, that the owner has chosen to keep it. Experience has shown that tigers and bears are alert to find means of escape, and that, if they escape, they are very certain to do harm of a serious nature. The possibility of a great danger has the same effect as the probability of a less one, and the law throws the risk of the venture on the person who introduces the peril into the community.

This remoteness of the opportunity of choice goes far to show that this risk is thrown upon the owner for other reasons than the ordinary one of imprudent conduct. It has been suggested that the liability stood upon remote inadvertence. /1/ But the law does not forbid a man to keep a menagerie, or deem it in any way blameworthy. It has applied nearly as strict a rule to dealings which are even more clearly beneficial to the community than a show of wild beasts.

This seems to be one of those cases where the ground of liability is to be sought in policy coupled with tradition, rather than in any form of blameworthiness, or the existence of such a chance to avoid doing the harm as a man is usually allowed. But the fact that remote inadvertence has been suggested for an explanation illustrates what has been said about the difficulty of deciding whether a given rule is founded on special grounds, or has been worked out within the sphere of negligence, when once a special rule has been laid down.

It is further to be noticed that there is no question of the defendant’s knowledge of the nature of tigers, although without that knowledge he cannot be said to have intelligently chosen to subject the community to danger. Here again even in the domain of knowledge the law applies its principle of averages. The fact that tigers and bears are dangerous is so generally known, that a man who keeps them is presumed to know their peculiarities. In other words, he does actually know that he has an animal with certain teeth, claws, and so forth, and he must find out the rest of what an average member of the community would know, at his peril.

What is true as to damages in general done by ferocious wild beasts is true as to a particular class of damages done by domestic cattle, namely, trespasses upon another’s land. This has been dealt with in former Lectures, and it is therefore needless to do more than to recall it here, and to call attention to the distinction based on experience and policy between damage which is and that which is not of a kind to be expected. Cattle generally stray and damage cultivated land when they get upon it. They only exceptionally hurt human beings.

I need not recur to the possible historical connection of either of these last forms of liability with the noxoe deditio, because, whether that origin is made out or not, the policy of the rule has been accepted as sound, and carried further in England within the last few years by the doctrine that a man who brings upon his land and keeps there anything likely to do mischief if it escape, must keep it in at his peril. /1/ The strictness of this principle will vary in different jurisdictions, as the balance varies between the advantages to the public and the dangers to individuals from the conduct in question. Danger of harm to others is not the only thing to be considered, as has been said already. The law allows some harms to be intentionally inflicted, and a fortiori some risks to be intentionally run. In some Western States a man is not required to keep his cattle fenced in. Some courts have refused to follow Rylands v. Fletcher. /2/ On the other hand, the principle has been applied to artificial reservoirs of water, to cesspools, to accumulations of snow and ice upon a building by reason of the form of its roof, and to party walls. /1/

In these cases, as in that of ferocious animals, it is no excuse that the defendant did not know, and could not have found out, the weak point from which the dangerous object escaped. The period of choice was further back, and, although he was not to blame, he was bound at his peril to know that the object was a continual threat to his neighbors, and that is enough to throw the risk of the business on him.

I now pass to cases one degree more complex than those so far considered. In these there must be another concomitant circumstance known to the party in addition to those of which the knowledge is necessarily or practically proved by his conduct. The cases which naturally suggest themselves again concern animals. Experience as interpreted by the English law has shown that dogs, rams, and bulls are in general of a tame and mild nature, and that, if any one of them does by chance exhibit a tendency to bite, butt, or gore, it is an exceptional phenomenon. Hence it is not the law that a man keeps dogs, rams, bulls, and other like tame animals at his peril as to the personal damages which they may inflict, unless he knows or has notice that the particular animal kept by him has the abnormal tendency which they do sometimes show. The law has, however, been brought a little nearer to actual experience by statute in many jurisdictions.

Now let us go one step farther still. A man keeps an unbroken and unruly horse, knowing it to be so. That is not enough to throw the risk of its behavior on him. The tendency of the known wildness is not dangerous generally, but only under particular circumstances. Add to keeping, the attempt to break the horse; still no danger to the public is disclosed. But if the place where the owner tries to break it is a crowded thoroughfare, the owner knows an additional circumstance which, according to common experience, makes this conduct dangerous, and therefore must take the risk of what harm may be done. /1/ On the other hand, if a man who was a good rider bought a horse with no appearance of vice and mounted it to ride home, there would be no such apparent danger as to make him answerable if the horse became unruly and did damage. /2/ Experience has measured the probabilities and draws the line between the two cases.

Whatever may be the true explanation of the rule applied to keeping tigers, or the principle of Rylands v. Fletcher, in the last cases we have entered the sphere of negligence, and, if we take a case lying somewhere between the two just stated, and add somewhat to the complexity of the circumstances, we shall find that both conduct and standard would probably be left without much discrimination to the jury, on the broad issue whether the defendant had acted as a prudent man would have done under the circumstances.

As to wrongs called malicious or intentional it is not necessary to mention the different classes a second time, and to find them a place in this series. As has been seen, they vary in the number of circumstances which must be known. Slander is conduct which is very generally at the risk of the speaker, because, as charges of the kind with which it deals are manifestly detrimental, the questions which practically arise for the most part concern the defence of truth or privilege. Deceit requires more, but still simple facts. Statements do not threaten the harm in question unless they are made under such circumstances as to naturally lead to action, and are made on insufficient grounds.

It is not, however, without significance, that certain wrongs are described in language importing intent. The harm in such cases is most frequently done intentionally, if intent to cause a certain harm is shown, there need to prove knowledge of facts which made it that harm would follow. Moreover, it is often much easier to prove intent directly, than to prove the knowledge which would make it unnecessary.

The cases in which a man is treated as the responsible cause of a given harm, on the one hand, extend beyond those in which his conduct was chosen in actual contemplation of that result, and in which, therefore, he may be to have chosen to cause that harm; and, on the other hand, they do not extend to all instances where the damages would not have happened but for some remote election his part. Generally speaking, the choice will be found to have extended further than a simple act, and to co-ordinated acts into conduct. Very commonly it will have extended further still, to some external consequence. But generally, also, it will be found to have stopped short of the consequence complained of.

The question in each case is whether the actual choice, or, in other words, the actually contemplated result, was near enough to the remoter result complained of to throw the peril of it upon the actor.

Many of the cases which have been put thus far are cases where the proximate cause of the loss was intended to be produced by the defendant. But it will be seen that the same result may be caused by a choice at different points. For instance, a man is sued for having caused his neighbor’s house to burn down. The simplest case is, that he actually intended to burn it down. If so, the length of the chain of physical causes intervening is of no importance, and has no bearing on the case.

But the choice may have stopped one step farther back. The defendant may have intended to light a fire on his own land, and may not have intended to burn the house. Then the nature of the intervening and concomitant physical causes becomes of the highest importance. The question will be the degree of danger attending the contemplated (and therefore chosen) effect of the defendant’s conduct under the circumstances known to him. If this was very plain and very great, as, for instance, if his conduct consisted in lighting stubble near a haystack close to the house, and if the manifest circumstances were that the house was of wood, the stubble very dry, and the wind in a dangerous quarter, the court would probably rule that he was liable. If the defendant lighted an ordinary fire in a fireplace in an adjoining house, having no knowledge that the fireplace was unsafely constructed, the court would probably rule that he was not liable. Midway, complicated and doubtful cases would go to the jury.

But the defendant may not even have intended to set the fire, and his conduct and intent may have been simply to fire a gun, or, remoter still, to walk across a room, in doing which he involuntarily upset a bottle of acid. So that cases may go to the jury by reason of the remoteness of the choice in the series of events, as well as because of the complexity of the circumstances attending the act or conduct. The difference is, perhaps, rather dramatic than substantial.

But the philosophical analysis of every wrong begins by determining what the defendant has actually chosen, that is to say, what his voluntary act or conduct has been, and what consequences he has actually contemplated as flowing from them, and then goes on to determine what dangers attended either the conduct under the known circumstances, or its contemplated consequence under the contemplated circumstances.

Take a case like the glancing of Sir Walter Tyrrel’s arrow. If an expert marksman contemplated that the arrow would hit a certain person, cadit qucoestio. If he contemplated that it would glance in the direction of another person, but contemplated no more than that, in order to judge of his liability we must go to the end of his fore-sight, and, assuming the foreseen event to happen, consider what the manifest danger was then. But if no such event was foreseen, the marksman must be judged by the circumstances known to him at the time of shooting.

The theory of torts may be summed up very simply. At the two extremes of the law are rules determined by policy without reference of any kind to morality. Certain harms a man may inflict even wickedly; for certain others he must answer, although his conduct has been prudent and beneficial to the community.

But in the main the law started from those intentional wrongs which are the simplest and most pronounced cases, as well as the nearest to the feeling of revenge which leads to self-redress. It thus naturally adopted the vocabulary, and in some degree the tests, of morals. But as the law has grown, even when its standards have continued to model themselves upon those of morality, they have necessarily become external, because they have considered, not the actual condition of the particular defendant, but whether his conduct would have been wrong in the fair average member of the community, whom he is expected to equal at his peril.

In general, this question will be determined by considering the degree of danger attending the act or conduct under the known circumstances. If there is danger that harm to another will follow, the act is generally wrong in the sense of the law.

But in some cases the defendant’s conduct may not have been morally wrong, and yet he may have chosen to inflict the harm, as where he has acted in fear of his life. In such cases he will be liable, or not, according as the law makes moral blameworthiness, within the limits explained above, the ground of liability, or deems it sufficient if the defendant has had reasonable warning of danger before acting. This distinction, however, is generally unimportant, and the known tendency of the act under the known circumstances to do harm may be accepted as the general test of conduct.

The tendency of a given act to cause harm under given circumstances must be determined by experience. And experience either at first hand or through the voice of the jury is continually working out concrete rules, which in form are still more external and still more remote from a reference to the moral condition of the defendant, than even the test of the prudent man which makes the first stage of the division between law and morals. It does this in the domain of wrongs described as intentional, as systematically as in those styled unintentional or negligent.

But while the law is thus continually adding to its specific rules, it does not adopt the coarse and impolitic principle that a man acts always at his peril. On the contrary, its concrete rules, as well as the general questions addressed to the jury, show that the defendant must have had at least a fair chance of avoiding the infliction of harm before he becomes answerable for such a consequence of his conduct. And it is certainly arguable that even a fair chance to avoid bringing harm to pass is not sufficient to throw upon a person the peril of his conduct, unless, judged by average standards, he is also to blame for what he does.



Applying FEA to Investigate the performance of Electrostatic Comb-Drive Actuators Utilized by on-a-chip systems

This study focuses on investigating the design parameters of lateral electrostatic comb-drive actuators, where the effect of these parameters on the actuation performance is explored using finite element analysis (FEA). This level of analysis is essential to the design process of system-on-a-chip microelectromechanical systems (MEMS) applications, where a comb drive can represent the main source of actuation within the chip system. Of particular interest to this study is the application of the electrostatic comb- drive motor as a fluidic pump in on-a-chip systems used for drug delivery or in cooling of microprocessors used in space vehicles. The commercial FE package ANSYS is utilized to construct a robust comb-drive model and solve its multiphysics interaction problem using the direct coupled-field analysis. In this model, the thickness, gap and overlap of the comb fingers are varied. The design of this model is also modulated to account for changes in the number of comb fingers and the applied driving voltage. The calculated comb displacement and generated electrostatic force are shown to be directly proportional to the number of comb fingers. Moreover, the generated electrostatic force is found to be inversely proportional to the gap between the comb fingers. As the thickness of these fingers increases, the displacement is found to increase for a given value of the driving voltage. The electrostatic force is also shown to be proportional to the offset (i.e., overlap) value between the fingers. To facilitate the use of the current study results in optimizing the design process of comb drives, an effort is made in the current work to condense these results into a compact nondimensional form that correlates the geometric and electrical parameters of the studied comb drive to the resulting displacement and force.

Cette e ́tude s’inte ́resse a` l’e ́tude par la me ́thode des e ́le ́ments finis des parame`tres de design des actionneurs e ́lectrostatiques late ́raux en peigne de meˆme que l’effet des parame`tres sur les performances des actionneurs. Une telle finesse d’analyse est ne ́cessaire a` la conception de dispositifs inte ́gre ́s dans les applications de syste`mes micro-e ́lectro-me ́caniques (MEMS) car l’entraˆınement en peigne peut constituer la principale source d’actionnement dans le syste`me inte ́gre ́. L’inte ́reˆt principal de cette approche est qu’elle peut s’appliquer a` la conception de moteurs a` peignes e ́lectrostatiques pour les pompes a` fluides dans les syste`mes sur une puce inte ́gre ́s pour la distribution de doses de me ́dicaments ou pour le refroidissement de micro-processeurs dans les ve ́hicules spatiaux. Un mode`le robuste de l’entraˆınement en peigne est construit graˆce au package logiciel d’e ́le ́ments finis ANSYS et pour re ́soudre le proble`me d’interaction multi-physique graˆce a` une analyse directe de champ couple ́. Dans le mode`le, on peut modifier l’e ́paisseur, l’espacement et le chevauchement entre les dents du peigne. La conception du mode`le prend aussi en compte la variation du nombre de dents du peigne et des valeurs de la tension d’entraˆınement. Le calcul des de ́placements des dents du peigne et de la force e ́lectrostatique ge ́ne ́re ́e montre leur de ́pendance directement proportionelle au nombre de dents du peigne. De plus, la force e ́lectrostatique ge ́ne ́re ́e est pour sa part inversement proportionnelle a` l’espacement entre les dents du peigne. Pour une valeur fixe de la tension d’entraˆınement, le de ́placement augmente avec l’e ́paisseur des dents du peigne. La force e ́lectrostatique est aussi proportionnelle a` l’offset entre les dents. L’utilisation de cette e ́tude pour l’optimisation du processus de conception de syste`mes d’entraˆınement a` peigne est facilite ́e par la pre ́sentation d’une forme compacte adimensionnelle corre ́lant les parame`tres ge ́ome ́triques et e ́lectriques de l’entraˆınement a` l’e ́tude au de ́placement et a` la force re ́sultants.


Hesham Ahmed, Walied Moussa, Wael Badawy, Medhat Moussa, “Applying FEA to Investigate the performance of Electrostatic Comb-Drive Actuators Utilized by on-a-chip systems” The Canadian Journal on Electrical and Computer Engineering, Vol. 27, No. 4, October 2002, pp. 195 – 200. Abstract


An Optimal Call Admission and Bandwidth Reservation Scheme for Future Wireless Networks

The next generation wireless networks promises availability of a wide variety of services. To be supported successfully, it is necessary to provide quality of service (QoS) between end-systems with the resources whose cost is discouragingly high. This paper proposes a new scheme for call admission and bandwidth reservation for the next generation wireless networks. The proposed scheme OPBR (optimal cell partition based bandwidth reservation) does an optimal partitioning of the cell to give high degree of call admission and successful handoff. In addition it offers effective bandwidth utilization and guarantee QoS. The performance of the scheme is done by analytical modeling and simulation experiments. A comparison with two different schemes (PBR and adaptive reservation) shows desirable results can be achieved by proposed scheme with better performance for various QoS parameters.

Download An Optimal Call Admission and Bandwidth Reservation Scheme for Future Wireless Networks

Mehboob Alam, Wael Badawy, Graham Jullien, “A Optimal Call Admission and Bandwidth Reservation Scheme for Future Wireless Networks,” Journal of Internet Technology, Vol. 4, No. 3, pp. 163-169, ISSN 1607-9264


Happy Birthday to my friend

I have this post to say happy birthday to you







Error-Free Computation of Daubechies Wavelets for Image Compression Applications

A novel encoding scheme for Daubechies wavelets is proposed. The technique eliminates the requirements to approximate the transformation matrix elements; rather, by using algebraic integers, it is possible to obtain exact representations for them. As a result, error-free calculations up to the final reconstruction step can be achieved, which provides considerable improvement in image reconstruction accuracy.

Published in:

Electronics Letters (Volume:39 , Issue: 5 )


K. A. Wahid, V. S. Dimitrov, G. A. Jullien and W. Badawy, “Error-Free Computation of Daubechies Wavelets for Image Compression Applications,” IEE Electronics Letters, Vol. 39, Issue 5 , 6 March 2003, pp. 428 -429


A New Call Admission and bandwidth reservation Scheme for Future Wireless Networks

The paper proposes a new scheme for call admission and bandwidth reservation for the next generation wireless networks. The proposed scheme OPBR (optimal cell partition based bandwidth reservation) does an optimal partitioning of the cell to give high degree of call admission and successful handoff. In addition it offers effective bandwidth utilization and guarantee QoS. The performance of the scheme is done by analytical modeling and simulation experiments. A comparison with two different schemes (PBR and adaptive reservation) shows desirable results can be achieved by proposed scheme with better performance for various QoS parameters.

Download A New Call Admission and Bandwidth Reservation Scheme for Future Wireless Networks

Mehboob Alam, Wael Badawy, Graham Jullien, “A New Call Admission and bandwidth reservation Scheme for Future Wireless Networks,” WSEAS Transactions on Communications, Vol. 1, Issue 1, pp. 197-203, ISSN 1109-2742


Sensing methods of Dielectrophories from Bulky Instruments to Lab-on-a-chip

Recently, the sensing methods for dielectrophoresis (DEP) have been changed from bulky instruments to lab-on-a-chip. Lab-on-a-chip based the dielectrophoresis phenomenon holds the promise to give biology the advantage of miniaturization for carrying out complex experiments. However, until now, there is an unmet need for lab-on-a-chip to effectively deal with the biological systems at the cell level.

Published in:

Circuits and Systems Magazine, IEEE (Volume:4 , Issue: 3 )


Yehya H. Ghallab, and Wael Badawy, “Sensing methods of Dielectrophories from Bulky Instruments to Lab-on-a-chip,” IEEE Circuit and Systems, Vol. 4, Issue 3, 2004


A Low Power Architecture for HASM Motion Tracking

This paper proposes low power VLSI architecture for motion tracking that can be used in online video applications such as in MPEG and VRML. The proposed architecture uses a hierarchical adaptive structured mesh (HASM) concept that generates a content-based video representation. The developed architecture shows the significant reducing of power consumption that is inherited in the HASM concept. The proposed architecture consists of two units: a motion estimation and motion compensation units.

The motion estimation (ME) architecture generates a progressive mesh code that represents a mesh topology and its motion vectors. ME reduces the power consumption since it (1) implements a successive splitting strategy to generate the mesh topology. The successive split allows the pipelined implementation of the processing elements. (2) It approximates the mesh nodes motion vector by using the three step search algorithm. (3) and it uses parallel units that reduce the power consumption at a fixed throughput.

The motion compensation (MC) architecture processes a reference frame, mesh nodes and motion vectors to predict a video frame using affine transformation to warp the texture with different mesh patches. The MC reduces the power consumption since it uses (1) a multiplication-free algorithm for affine transformation. (2) It uses parallel threads in which each thread implements a pipelined chain of scalable affine units to compute the affine transformation of each patch.

The architecture has been prototyped using top-down low-power design methodology. The performance of the architecture has been analyzed in terms of video construction quality, power and delay.

Wael Badawy and Magdy Bayoumi “A Low Power Architecture for HASM Motion Tracking,” The Journal of VLSI Signal Processing Systems for Signal, Image, and Video Technology, May 2004, Vol. 37, Issue 1, pp. 111-127