If, in performing an illegal contract, one is unconscious of any question as to its legality, his performance may properly be said to be in misreliance on the contract {ante, Sec. 10). And the fact that one's ignorance of the illegality of a transaction is due to his own negligence is generally immaterial {ante, Sec. 15). But if one believes his contract to be illegal, or indeed is conscious of a doubt as to its legality, he assumes the risk and cannot be said to rely upon the contract {ante, Sec. 16). No case arising out of an illegal contract has been found in which the denial of relief is placed squarely upon this ground. As in the case of contracts unenforceable because of the Statute of Frauds {ante, Sec. 94), this is probably due in part to a failure to realize that the obligation to make restitution rests upon the doctrine of misreliance, and in part to the fact that, unless the question of legality is a subject of communication between the parties, the state of the plaintiff's mind on the question is difficult of satisfactory proof.