This section is from the book "The Law Of Contracts", by Samuel Williston. Also available from Amazon: Treatise on the Law of Contracts.
The formation of contracts requires the existence of parties capable of contracting, but capacity of any person to contract is to be presumed unless he falls within one of the classes of persons who are held by the law to have no capacity, or only a limited capacity to contract. These classes are:
Infante,
The extent to which agents and fiduciaries of various kinds are personally bound by the contracts which they make as such presents an analogous question which may be considered in the same connection. Whether a party has capacity to contract is determined by the law of the place of the contract,43 in accordance with the general rule that the validity of a contract and its construction are determined by that law.44
 
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