§ 12. Capacity To Contract
(1) No one can be bound by contract who has not legal capacity to incur at least voidable contractual duties. Capacity to contract may be partial and its existence in respect of a particular transaction may depend upon the nature of the transaction or upon other circumstances.
(a) under guardianship, or
(b) an infant, or
(c) mentally ill or defective, or
a. Total and partial incapacity. Capacity, as here used, means the legal power which a normal person would have under the same circumstances. See Restatement, Second, Agency § 20; Restatement, Second, Trusts § 18. Incapacity may be total, as in cases where extreme physical or mental disability prevents manifestation of assent to the transaction, or in cases of mental illness after a guardian has been appointed. Often, however, lack of capacity merely renders contracts voidable. See § 7. Incapacity sometimes relates only to particular types of transactions; on the other hand, persons whose capacity is limited in most circumstances may be bound by particular types of transactions. In cases of partial disability, the law of mistake or of misrepresentation, duress and undue influence may be relevant. See Chapters 6 and 7, particularly §§ 153, 157, 161(d), 163, 164, 167, 169(c) and 177, Comment b to § 172 and Comment c to § 175.
b. Types of incapacity. Historically, the
principal categories of natural persons having no capacity or limited capacity
to contract were married women, infants, and insane persons. Those formerly
referred to as insane are included in the more modern phrase "mentally
ill," and mentally defective persons are treated similarly. Statutes
sometimes authorize the appointment of guardians for habitual drunkards,
narcotics addicts, spendthrifts, aged persons or convicts as in cases of mental
illness. Even without the appointment of a guardian, civil powers of convicts
may be suspended in whole or in part during imprisonment; and American Indians
are for some purposes treated as wards of the
c. Inability to manifest assent. In order to incur a contractual duty, a party must make a promise, manifesting his intention; in most cases he must manifest assent to a bargain. See §§ 2, 17, 18. The conduct of a party is not effective as a manifestation of his assent unless he intends to engage in the conduct. See § 19. Hence if physical disability prevents a person from acting, or if mental disability is so extreme that he cannot form the necessary intent, there is no contract. Similarly, even if he intends to engage in the conduct, there is no contract if the other party knows or has reason to know that he does not intend the resulting appearance of assent. See § 20. In such cases it is proper to say that incapacity prevents the formation of a contract.
d. Married women. At common law a married woman had no capacity to incur contractual duties, although courts of equity recognized a limited power with respect to property conveyed to her separate use. Modern statutes in most States have given married women full power to contract, and they are therefore omitted from the list in subsection (2) of persons who may not have full capacity. In some States, however, capacity is still denied with respect to particular types of contracts, such as contracts between husband and wife, contracts of suretyship, contracts for the sale of real property, or contracts relating to the management of community property.
e. Artificial persons. The contractual powers of artificial persons such as corporations and governmental agencies are beyond the scope of the Restatement of this Subject. The tendency of modern legislation is to restrict the assertion of the defense of ultra vires by business corporations, and in effect to give them full capacity; what was once lack of capacity then resembles lack of authority as used in the law of agency. See Model Business Corporation Act § 6 (1961). Where partnerships or unincorporated associations have no power to contract as such, contracts made in their names bind the members instead. Compare Restatement, Second, Agency § 20; Restatement, Second, Trusts §§ 97, 98.
f. Necessaries. Persons having no capacity or limited capacity to contract are often liable for necessaries furnished to them or to their wives or children. Though often treated as contractual, such liabilities are quasi-contractual: the liability is measured by the value of the necessaries rather than by the terms of the promise. The rules governing such liabilities are beyond the scope of the Restatement of this Subject. See Restatement of Restitution §§ 62, 112-17, 139.