to be part of the Principle of
Individuation, as it is only space and time that make the multiplicity
of similar objects a possibility. But multiplicity itself also admits
of variety; multiplicity and diversity are not only quantitative, but
also qualitative. How is it that there is such a thing as qualitative
diversity, especially in ethical matters? Or have I fallen into an
error the opposite of that in which Leibnitz fell with his _identitas
indiscernibilium_?

The chief cause of intellectual diversity is to be found in the
brain and nervous system. This is a fact which somewhat lessens the
obscurity of the subject. With the brutes the intellect and the brain
are strictly adapted to their aims and needs. With man alone there
is now and then, by way of exception, a superfluity, which, if it is
abundant, may yield genius. But ethical diversity, it seems, proceeds
immediately from the will. Otherwise ethical character would not be
above and beyond time, as it is only in the individual that intellect
and will are united. The will is above and beyond time, and eternal;
and character is innate; that is to say, it is sprung from the same
eternity, and therefore it does not admit of any but a transcendental
explanation.

Perhaps some one will come after me who will throw light into this
dark abyss.

MORAL INSTINCT.

An act done by instinct differs from every other kind of act in that
an understanding of its object does not precede it but follows upon
it. Instinct is therefore a rule of action given _a priori_. We may be
unaware of the object to which it is directed, as no understanding of
it is necessary to its attainment. On the other hand, if an act is
done by an exercise of reason or intelligence, it proceeds according
to a rule which the understanding has itself devised for the purpose
of carrying out a preconceived aim. Hence it is that action according
to rule may miss its aim, while instinct is infallible.

On the _a priori_ character of instinct we may compare what Plato says
in the _Philebus_. With Plato instinct is a reminiscence of something
which a man has never actually experienced in his lifetime; in the
same way as, in the _Phaedo_ and elsewhere, everything that a man
learns is regarded as a reminiscence. He has no other word to express
the _a priori_ element in all experience.

There are, then, three things that are _a priori_:

(1) Theoretical Reason, in other words, the conditions which mak