because it would be absurd to suppose that any man would voluntarily assist to establish or support a government that would punish himself for acts which he himself did not know to be crimes. But a man may reasonably unite with his fellow-men to maintain a government to punish those acts which he himself considers criminal, and may reasonably acquiesce in his own liability to be punished for such acts. As those are the only grounds on which any one can be supposed to render any voluntary support to a government, it follows that a government formed by voluntary association, and of course having no powers except such as _all_ the associates have consented that it may have, can have no power to punish a man for acts which he did not himself know to be criminal. The safety of society, which is the only object of the criminal law, requires only that those acts _which are understood by mankind at large to be intrinsically criminal_, should be punished as crimes. The remaining few (if there are any) may safely be left to go unpunished. Nor does the safety of society require that any individuals, other than those who have sufficient mental capacity to understand that their acts are criminal, should be criminally punished. All others may safely be left to their liability, under the _civil_ law, to compensate for their unintentional wrongs. The only real object of this absurd and atrocious doctrine, that "ignorance of the law (that is, of crime) excuses no one," and that "every one is bound to know the _criminal_ law," (that is, bound to know what is a crime,) is to maintain an entirely arbitrary authority on the part of the government, and to deny to the people all right to judge for themselves what their own rights and liberties are. In other words, the whole object of the doctrine is to deny to the people themselves all right to judge what statutes and other acts of the government are consistent or inconsistent with their own rights and liberties; and thus to reduce the people to the condition of mere slaves to a despotic power, such as the people themselves would never have voluntarily established, and the justice of whose laws the people themselves cannot understand. Under the true trial by jury all tyranny of this kind would be abolished. A jury would not only judge what acts were really criminal, but they would judge of the mental capacity of an accused person, and of his opportunities for understanding the true character of his conduct. In short, they would judge of his moral intent from all the circumstances of the case, and acquit him, if they had any reasonable doubt that he knew that he was committing a crime.[104]