legislatures and courts have once made criminal. Not only are criminal
statutes always dying by repeal or repeated violation, but every time a
legislature meets, it changes penalties for existing crimes and makes
criminal certain acts that were not forbidden before.

Judging from the kind of men sent to the State legislatures and to
Congress, the fact that certain things are forbidden does not mean that
these things are necessarily evil; but rather, that politicians believe
there is a demand for such legislation from the class of society that is
most powerful in political action. No one who examines the question can
be satisfied that a thing is intrinsically wrong because it is forbidden
by a legislative body.

Other more or less popular opinions of the way to determine right or
wrong are found to be no more satisfactory. Many believe that the
question of whether an act is right or wrong is to be settled by a
religious doctrine; but the difficulties are still greater in this
direction. First of all, this involves a thorough and judicial inquiry
into the merits of many, if not all, forms of religion, an investigation
which has never been made, and from the nature of things cannot be made.
The fact is, that one's religious opinions are settled long before he
begins to investigate and quite by other processes than reason. Then,
too, all religious precepts rest on interpretation, and even the things
that seem the plainest have ever been subject to manifold and sometimes
conflicting construction. Few if any religious commands can be, or ever
were, implicitly relied on without interpretation. The command, "Thou
shalt not kill," seems plain, but does even this furnish an infallible
rule of conduct?

Of course this commandment could not be meant to forbid killing animals.