their physical and psychical constitution, as it has ultimately taken
place in the organism by the successive evolutions of forms which have
gradually become permanent, and are perpetuated by embryogenic
reproduction. This reproduction is in its turn the absolute condition of
psychical and organic facts, which are thus manifested as primitive
facts in the new life of the individual. By this law, the psychical
facts, whether elementary or complex, as they occur in the individual up
to the point of their evolution, have the necessary conditions of
possibility, and may therefore be termed a _priori_ with respect to the
laws of evolution, and to the hereditary permanence of acts performed in
the former environment of the organism at the time when they appeared.

This conception of a _priori_ is, it must be admitted, very different
from that of transcendental philosophers, who seek to prove either that
an independent artificer has not only produced the various organic forms
in their present complexity, and has specially provided the spiritual
subject with its category of thought, independently of all experience;
or else they assert the intrinsic existence of such forms in the spirit,
from the beginning of time.

In this way, as we have already said, we must not only collect the facts
which abound in history and ethnology respecting the general teaching of
myths, but we must also observe introspectively, and by pursuing the
experimental method, the primitive and fundamental psychical facts, so
as to discover the a priori conditions of the myth itself. We must
ascertain, from a careful psychological examination, the absolutely
primitive origin of all mythical representations, and how these are in
their turn the actual historical result of the same conditions, as they
existed prior to their manifestations.