hich 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]

[Footnote 103: This presumption, founded upon age alone, is as absurd in
civil matters as in criminal. What can be more entirely ludicrous than
the idea that all men (not manifestly imbecile) become mentally
competent to make all contracts whatsoever on the day they become
twenty-one years of age?--and that, previous to that day, no man becomes
competent to make any contract whatever, except for the present supply
of the most obvious wants of nature? In reason, a man's _legal_
competency to make _binding_ contracts, in any and every case whatever,
depends wholly upon his _mental