This doctrine, that "ignorance of the law excuses no one," is constantly repeated in the form that "every one is bound to know the law." The doctrine is true in civil matters, especially in contracts, so far as this: that no man, who has the _ordinary_ capacity to make reasonable contracts, can escape the consequences of his own agreement, on the ground that he did not know the law applicable to it. When a man makes a contract, he gives the other party rights; and he must of necessity judge for himself, and take his own risk, as to what those rights are,--otherwise the contract would not be binding, and men could not make contracts that would convey rights to each other. Besides, the capacity to make reasonable contracts, _implies and includes_ a capacity to form a reasonable judgment as to the law applicable to them. But in _criminal_ matters, where the question is one of punishment, or not; where no second party has acquired any right to have the crime punished, unless it were committed with criminal intent, (but only to have it compensated for by damages in a civil suit;) and when the criminal intent is the only moral justification for the punishment, the principle does not apply, and a man is bound to know the law _only as well as he reasonably may_. The criminal law requires neither impossibilities nor extraordinaries of any one. It requires only thoughtfulness and a good conscience. It requires only that a man fairly and properly use the judgment he possesses, and the means he has of learning his duty. It requires of him only the same care to know his duty in regard to the law, that he is morally bound to use in other matters of equal importance. _And this care it does require of him._ Any ignorance of the law, therefore, that is unnecessary, or that arises from indifference or disregard of one's duty, is no excuse. An accused person, therefore, may be rightfully held responsible for such a knowledge of the law as is common to men in general, having no greater natural capacities than himself, and no greater opportunities for learning the law. And he can rightfully be held to no greater knowledge of the law than this. To hold him responsible for a greater knowledge of the law than is common to mankind, when other things are equal, would be gross injustice and cruelty. The mass of mankind can give but little of their attention to acquiring a knowledge of the law. Their other duties in life forbid it. Of course, they cannot investigate abstruse or difficult questions. All that can rightfully be required of each of them, then, is that he exercise such a candid and conscientious judgment as it is common for mankind generally to exercise in such matters. If he have done this, it would be monstrous to punish him criminally for his errors; errors not of conscience, but only of judgment. It would also be contrary to the first principles of a free government (that is, a government formed by voluntary association) to punish men in such cases,