as he ever does. Contact with air and food is all that is needed, and
there is nothing to be learned. These actions, though they are performed
by the nervous system, we do not class as psychical, because they are
nearly or quite unattended by consciousness. The psychical life of the
lowest animals consists of a few simple acts directed toward the
securing of food and the avoidance of danger, and these acts we are in
the habit of classing as instinctive. They are so simple, so few, and so
often repeated, that the tendency to perform them is completely
organized in the nervous system before birth. The animal takes care of
himself as soon as he begins to live. He has nothing to learn, and his
career is a simple repetition of the careers of countless ancestors.
With him heredity is everything, and his individual experience is next
to nothing.

As we ascend the animal scale till we come to the higher birds and
mammals, we find a very interesting and remarkable change beginning. The
general increase of intelligence involves an increasing variety and
complication of experiences. The acts which the animal performs in the
course of its life become far more numerous, far more various, and far
more complex. They are therefore severally repeated with less frequency
in the lifetime of each individual. Consequently the tendency to perform
them is not completely organized in the nervous system of the offspring
before birth. The short period of ante-natal existence does not afford
time enough for the organization of so many and such complex habitudes
and capacities. The process which in the lower animals is completed
before birth is in the higher animals left to be completed after birth.
When the creature begins its life it is not completely organized.
Instead of the power of doing all the things which its parents did, it
starts with the power of doing only some few of them; for the rest it
has only latent capacities which need to be brought out by its