The formula that mistake or ignorance of law excuses no one is often used where the lack of relief is due to a more fundamental difficulty which would likewise have precluded relief if the mistake had been one of fact. Thus mistake by one party of the law governing his antecedent rights or his present agreement can afford no ground for relief if the mistake was not known to or induced by the other party,36 unless there is the further element of lack or failure of consideration.

Again the distinction must be observed between (1) a mistake of law in the expression of an intended contract; (2) a mistake of law concerning legal consequences of a contract which were not covered by any antecedent agreement of the parties; and (3), a mistake of law concerning the rights of the parties prior to the transaction in question. A mistake of the first sort is not likely to occur except in connection with writings. A mistake of the second or third kinds may occur in connection with written or oral transactions whether executory or executed.

It must be remembered also that in any event a mistake of law to justify rescission must have related to a question the answer to which was assumed as part of the fundamental basis of the transaction. A mistake of law as to some collateral mattranslated by Pound, Readings in Roman Law (2d ed.), 37.

32 Sec. 110, translated, supra, Sec. 1546, n. 37.

33 Baudry-Lacantinerie, Traite de Droit Civil (2d ed.) XI, Sec. 70; translated by Pound, Readings in Roman Law (2d ed.), 37.

34 Civ. Code, Art. 1100.

35See Pound, Readings in Roman Law (2d ed.), 37-43; Philippine Sugar Estates Development Co. v. Government of Philippine Ids., 247 U. S. 386, 88 Sup. Ct. 513, 62 L. Ed. 1177.

36See Georgia Code, Sec.4575; Marshall v. Westrope, 98 la. 324, 67 N. W. 257; Wheaton, etc., Co. v. Boston, 204 Mass. 218, 00 N. E. 508; Dow v. Ker, Spesrs Eq. 413; Neff v. Rains, 33 Wis. 680.

ter bearing on the motive for entering into the transaction on no principle can have greater importance than a corresponding mistake of fact. This will explain the decision of many cases where relief has been denied, professedly because the mistake was one of law. When the recognized exceptions to any general principle denying relief for that reason are taken into account, it will be seen that the scope of the rule, even in jurisdictions which fully recognize it, is much restricted. These exceptions may now be considered.37