Once the law had become committed to this view, it could not be maintained that problems concerning the contracts of persons of unsound mind could be solved by the simple formula: a contract requires the assent of both parties; a person of unsound mind is incapable of assenting; therefore no contract can come into existence between parties of whom one is of unsound mind. This appears not to have been appreciated at first. Consider, for instance, the case of Gore v Gibson [7] . To an action by an indorsee of a bill of exchange against the indorser, the defendant pleaded that at the time of making the indorsement he was unable (through intoxication) to comprehend the meaning, nature or effect of the indorsement, and that the plaintiff then had notice of this. The position was put clearly by Baron Parke: "The averment in this plea that the defendant indorsed the bill, means merely that he wrote his name upon it; then the plea goes on to state, as matter of avoidance, that the act of so writing his name is not obligatory on him, because he was in fact non compos mentis when he did it" [1] . Earlier he had said: "But where the party, when he enters into the contract, is in such a state of drunkenness as not to know what he is doing, and particularly when it appears that this was known to the other party, the contract is void altogether, and he cannot be compelled to perform it". (As the context shows, void here meant voidable: Matthews v Baxter [2] ). Yet in this very case Pollock C.B. [3] spoke of a contract requiring the assent of both parties, giving that as the reason for saying that when one of the parties was incapable of assenting there could be no binding contract. Alderson B. said: "When it is shewn that the contract by indorsement was made when the defendant was in such a state of drunkenness that he did not know what he was doing, and especially when it appears that the plaintiff knew it, I cannot doubt that the contract is void altogether" [4] . (Again, void meant voidable, as was to be pointed out in Matthews v Baxter [2] ). Although this acknowledged that a contract was made by the indorsement, and that in some circumstances the contract could not be avoided, the learned Baron added: "It is just the same as if the defendant had written his name upon the bill in his sleep, in a state of somnambulism". In such a case, however, the signature would simply not be a signature having any relation to the bill of exchange at all. Though it would be on the same piece of paper, it would not be an indorsement of the bill. But a person who, having in truth indorsed the bill, sets up his inability to understand what he was doing, is necessarily seeking to avoid a contract made in fact. And so it was laid down in Matthews v Baxter [2] , the view of Parke B., that the mental incapacity of one of the contracting parties is "matter of avoidance" only, being thus affirmed.