Logic of Contracting

According to the will theory of contract, which was dominant in the 19th century and still exerts a strong influence, a contract is not presumed valid unless all parties agree to it voluntarily, either tacitly or explicitly, without coercion. Lysander Spooner, a 19th century lawyer and staunch supporter of a right of contract between individuals, in his essay No Treason, argues that a supposed social contract cannot be used to justify governmental actions such as taxation, because government will initiate force against anyone who does not wish to enter into such a contract. As a result, he maintains that such an agreement is not voluntary and therefore cannot be considered a legitimate contract at all.

Modern Anglo-American law, like European civil law, is based on a will theory of contract, according to which all terms of a contract are binding on the parties because they chose those terms for themselves. This was less true when Hobbes wrote Leviathan; then, more importance was attached to consideration, meaning a mutual exchange of benefits necessary to the formation of a valid contract, and most contracts had implicit terms that arose from the nature of the contractual relationship rather than from the choices made by the parties. Accordingly, it has been argued that social contract theory is more consistent with the contract law of the time of Hobbes and Locke than with the contract law of our time, and that features in the social contract which seem anomalous to us, such as the belief that we are bound by a contract formulated by our distant ancestors, would not have seemed as strange to Hobbes' contemporaries as they do to us.