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 ＇254＇ 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 ＇255＇ 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 ＇256＇ 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 ＇258＇ 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 witnes