identity between man and animals to be established by the adequate
consideration of the faculties, the psychical elements of consciousness
and intelligence, and the mode of their spontaneous exercise; and I
believe the superiority of man to consist not so much in new faculties
as in the reflex effect upon themselves of those he possesses in common
with the animals. The old adage confirms this theory: _Homo duplex_.

No one now doubts that animals feel, hear, remember, and the like, while
man is able to exercise his will, to feel, to remember, deliberately to
consider all his actions and functions, because he not only possesses
the direct and spontaneous intuition with respect to himself and things
in general which he has in common with animals, but he has an intuitive
knowledge of that intuition itself, and in this way he multiplies within
himself the exercise of his whole psychical life. We find the ultimate
cause of this return upon himself, and his intuition of things, in his
deliberate will, which does not only immediately command his body and
his manifold relative functions, but also the complex range of his
psychical acts. This fact, which as I believe has not been observed
before, is of great importance. It is manifest that the difference
between man and other animals does not consist in the diversity or
discrepancy of the elements of the intelligence, but in its reflex
action on itself; an action which certainly has its conditions fixed by
the organic and physiological composition of the brain.

If it should be said that the traditional opinion of science, as well as
the general sentence of mankind, have always regarded reflection as the
basis of the difference between animals and man, so that there is no
novelty in our principle, the assertion is erroneous. Reflection, as an
inward psychical fact, has certainly been observed by psychologists and
philosophers in all civilized times, and instinctively by every one; nor