The mental capacity of a person to make reasonable contracts, is the only criterion, by which to determine his legal capacity to make obligatory contracts. And his mental capacity to make reasonable contracts is certainly not to be determined by the fact that he is, or is not, twenty-one years of age. There would be just as much sense in saying that it was to be determined by his height or his weight, as there is in saying that it should be determined by his age. Nearly all persons, male and female, are mentally competent to make reasonable contracts, long before they are twenty-one years of age. And as soon as they are mentally competent to make reasonable contracts, they have the same natural right to make them, that they ever can have. And their contracts have the same natural "obligation" that they ever can have. If a person's mental capacity to make reasonable contracts be drawn in question, that is a question of fact, to be ascertained by the same tribunal that is to ascertain all the other facts involved in the case. It certainly is not to be determined by any arbitrary legislation, that shall deprive any one of his natural right to make contracts. 2. All the State laws, that do now forbid, or that have heretofore forbidden married women to make any or all contracts, that they are, or were, mentally competent to make reasonably, are violations of their natural right to make their own contracts. A married woman has the same natural right to acquire and hold property, and to make all contracts that she is mentally competent to make reasonably, as has a married man, or any other man. And any law invalidating her contracts, or forbidding her to enter into contracts, on the ground of her being married, are not only absurd and outrageous in themselves, but are also as plainly violations of that provision of the constitution, which forbids any State to pass any law impairing the natural obligation of contracts, as would be laws invalidating or prohibiting similar contracts by married men. 3. All those State laws, commonly called acts of incorporation, by which a certain number of persons are licensed to contract debts, without having their individual properties held liable to pay them, are laws impairing the natural obligation of their contracts. On natural principles of law and reason, these persons are simply partners; and their private properties, like those of any other partners, should be held liable for their partnership debts. Like any other partners, they take the profits of their business, if there be any profits. And they are naturally bound to take all the risks of their business, as in the case of any other business. For a law to say that, if they make any profits, they may put them all into their own pockets, but that, if they make a loss, they may throw it upon their creditors, is an absurdity and an outrage. Such a law is plainly a law impairing the natural obligation of their contracts.