has somewhat fewer instincts than those possessed by the
animals which come next to him in the series." On the other hand, Prof.
Wm. James says ("Principles of Psychology," Vol. II. page 289.) that man
is probably the animal with most instincts. The true position is that
man and the higher animals have fewer complete and self-sufficing
instincts than those which stand lower in the scale of mental
evolution, but that they have an equally large or perhaps larger mass of
instinctive raw material which may furnish the stuff to be elaborated
by intelligent processes. There is, perhaps, a greater abundance of
the primary tissue of experience to be refashioned and integrated by
secondary modification; there is probably the same differentiation in
relation to the determining biological ends, but there is at the outset
less differentiation of the particular and specific modes of behaviour.
The specialised instinctive performances and their concomitant
experience-complexes are at the outset more indefinite. Only through
acquired connections, correlated with experience, do they become
definitely organised.

The full working-out of the delicate and subtle relationship of instinct
and educability--that is, of the hereditary and the acquired factors in
the mental life--is the task which lies before genetic and comparative
psychology. They interact throughout the whole of life, and their
interactions are very complex. No one can read the chapters of "The
Descent of Man" which Darwin devotes to a consideration of the mental
characters of man and animals without noticing, on the one hand, how
sedulous he is in his search for hereditary foundations, and, on the
other hand, how fully he realises the importance of acquired habits of
mind. The fact that educability itself has innate tendencies--is in fact
a partially differentiated educability--renders the unravelling of the
factors of mental progress all the more difficult.

In his comparison of the mental powers of men and animals it was
essential that Darwin should lay stress on points of similarity rather
than on points of difference. Seeking to establish a doctrine of
evolution, with its basal concept of continuity of process and community
of character, he was bound to render clear and to emphasise the
contention that the difference in mind between man and the higher
animals, great as it is, is one of degree and not of kind. To this end
Darwin not only recorded a large number of valua