Pacta sunt servanda and classical contract doctrine

A final word on pacta sunt servanda. We have seen how the praetor's promise, as related by Ulpian in D. 2, 14, 7, 7, was turned into this general maxim by the canon lawyers.^[2997] Its import was, first of all, to assert the principle of consensualism: all pacts are binding, regardless of whether they are clothed or naked.

" [IJf there is one thing which more than another public policy requires it is that men of full age and competent understanding shall have the utmost liberty of contracting, and that their contracts when entered into freely and voluntarily shall be held sacred and shall be enforced by Courts of justice. Therefore, you have this paramount public policy to consider—that you are not lightly to interfere with this freedom of contract."

This statement of Sir George Jessel MR^{[2998] [2999] is representative of the attitude prevailing in the 19th century.[3000] Everybody is free to decide whether he wants to enter into a contract or not ("Abschlussfreiheit"), and it is up to the parties to determine the content of their transaction ("Inhaltsfreiheit").[3001] 7 Such content, of course, may not be illegal or immoral. But apart from that, there is no judicial interference. In particular, the validity of a contract does not depend on the (objective) adequacy of consideration. Equality in the values exchanged is immaterial. It is for the parties to make their bargain, not for the courts. The courts are merely concerned with the fairness of the bargaining process, the assumption being that the result of fair negotiations is likely to be substantially fair too. Hence, for instance, the defences of fraud, misrepresentation and duress. But once it has been established that the formation of the contract has not been affected by these kinds of cognitive weaknesses,[3002] the parties are bound by their agreement. This was the principle in Roman law, where fides demanded that a man must keep his word.[3003] Unilateral denunciation of a contract was therefore, in general, excluded. The canon lawyers, of course, eagerly reasserted the moral precept of faithfulness requiring that a promise must be honoured; and so did, under more secular auspices, the natural lawyers.}

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