t discovered merely by reason. To put the affair, therefore, to
this trial, let us chuse any inanimate object, such as an oak or elm;
and let us suppose, that by the dropping of its seed, it produces a
sapling below it, which springing up by degrees, at last overtops and
destroys the parent tree: I ask, if in this instance there be wanting
any relation, which is discoverable in parricide or ingratitude? Is
not the one tree the cause of the other's existence; and the latter the
cause of the destruction of the former, in the same manner as when a
child murders his parent? It is not sufficient to reply, that a choice
or will is wanting. For in the case of parricide, a will does not give
rise to any DIFFERENT relations, but is only the cause from which the
action is derived; and consequently produces the same relations, that in
the oak or elm arise from some other principles. It is a will or choice,
that determines a man to kill his parent; and they are the laws of
matter and motion, that determine a sapling to destroy the oak, from
which it sprung. Here then the same relations have different causes; but
still the relations are the same: And as their discovery is not in both
cases attended with a notion of immorality, it follows, that that notion
does not arise from such a discovery.

But to chuse an instance, still more resembling; I would fain ask any
one, why incest in the human species is criminal, and why the very same
action, and the same relations in animals have not the smallest moral
turpitude and deformity? If it be answered, that this action is innocent
in animals, because they have not reason sufficient to discover its
turpitude; but that man, being endowed with that faculty which ought to
restrain him to his duty, the same action instantly becomes criminal to
him; should this be said, I would reply, that this is evidently
arguing in a circle. For before reason can perceive this turpitude, the
turpitude must exist; and consequently is independent of the decisions
of our reason, and is their object more properly than their effect.
According to this system, then, every animal, that has sense, and
appetite, and will; that is, every animal must be susceptible of all the
same virtues and vices, for which we ascribe praise and blame to human
creatures. All the difference is, that our superior reason may serve to
discover the vice or virtue, and by that means may augment the blame
or praise: But still this discovery sup