e the term
"instinctive" so as to comprise all congenital modes of behaviour which
contribute to experience, we are in a position to grasp the view that
the net result in consciousness constitutes what we may term the
primary tissue of experience. To the development of this experience each
instinctive act contributes. The nature and manner of organisation of
this primary tissue of experience are dependent on inherited biological
aptitudes; but they are from the outset onwards subject to secondary
development dependent on acquired aptitudes. Biological values are
supplemented by psychological values in terms of satisfaction or the
reverse.

In our study of instinct we have to select some particular phase of
animal behaviour and isolate it so far as is possible from the life of
which it is a part. But the animal is a going concern, restlessly active
in many ways. Many instinctive performances, as Darwin pointed out
("Origin of Species" (6th edition), page 206.), are serial in their
nature. But the whole of active life is a serial and coordinated
business. The particular instinctive performance is only an episode in
a life-history, and every mode of behaviour is more or less closely
correlated with other modes. This coordination of behaviour is
accompanied by a correlation of the modes of primary experience. We may
classify the instinctive modes of behaviour and their accompanying modes
of instinctive experience under as many heads as may be convenient
for our purposes of interpretation, and label them instincts of
self-preservation, of pugnacity, of acquisition, the reproductive
instincts, the parental instincts, and so forth. An instinct, in this
sense of the term (for example the parental instinct), may be described
as a specialised part of the primary tissue of experience differentiated
in relation to some definite biological end. Under such an instinct
will fall a large number of particular and often well-defined modes of
behaviour, each with its own peculiar mode of experience.

It is no doubt exceedingly difficult as a matter of observation and of
inference securely based thereon to distinguish what is primary from
what is in part due to secondary acquisition--a fact which Darwin fully
appreciated. Animals are educable in different degrees; but where they
are educable they begin to profit by experience from the first. Only,
therefore, on the occasion of the first instinctive act of a given type
can the experience