This section is from the book "American Commercial Law Series ", by Alfred W. Bays. Also available from Amazon: American commercial law series.
A party to a contract is a person who by himself or his agent, has a part in making the contract.
A contract carries an adversary idea, that is to say, an arrangement of those who form it on different sides having interests that may in fact be mutual but which may at any time become antagonistic through the failure of one side to perform and thus force the other into court for the protection of his interests. Accordingly every contract must have at least two sides; but it may have more. There may be any number of persons on any side. A "party" is any person who by himself or through his agent has been a maker thereof. No other person is a party, even though named in the contract, and, generally speaking, can have no rights or liabilities thereon.
A natural person has a full capacity to contract when of legal age and in possession of the natural faculties, unless the law has imposed upon him, as a member of a class, a disability. A corporation has such capacity as the sovereign has bestowed upon it.
We note at the outset that unless a person is not of full age, or is not in the possession of the ordinary natural faculties, or is not a member of a class which the law, for reasons of public policy, has placed under a total or partial disability, he has the full capacity to contract; he is free to impose upon himself whatsoever contractual obligations he will. We are, then, concerned only with those exceptional cases, in which some disability is imposed by the law. The chief of these are, (a) minors, (b) married women, (c) insane persons, (d) drunkards, (e) aliens, and (f) artificial persons or corporations.
The class composed of minors is of course far the most important as it is a class in which every natural person is for a time a member.