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NATURE 
THURSDAY, FEBRUARY 5, 1914. 
THE SCIENCE AND PHILOSOPHY OF 
INSTINCT. 
Instinct and Experience. By Prof. C. Lloyd 
Morgan, F.R.S. (London: Methuen and Co., 
Ltd., 1912.) Pp. xvii+299. 5s. net. 
HIS is an important contribution to the 
much-discussed subject of instinct. It re- 
veals a perplexing discrepancy of opinion among 
those who have recently given special attention 
to the nature of instinctive behaviour in its bio- 
logical and psychological aspects, and the way in 
which the author deals with the views of Bergson, 
Driesch, McDougall, Myers, Stout, and many 
others is a model of what scientific discussion 
should be. Perhaps it does not make the book 
easier to read, but there is a fascination in his 
Darwin-like method of anticipating difficulties, 
answering criticisms that have been made, and 
forestalling others that will be forthcoming all the 
same. It is now many years since Prof. Lloyd 
Morgan began a new chapter in the study of in- 
stinct, marked by clear-cut experimental work on 
one hand, and philosophical insight on the other ; 
and in this new book he has made us again his 
debtors. He is always lucid and always fair; 
and his vivid, arresting style is especially 
welcome when the subject-matter is necessarily 
difficult. . 
Let us quote a fine summary of much research 
and thought :— 
“Instinctive behaviour is that which is, on its 
first occurrence, independent of prior experience; 
which tends to the well-being of the individual and 
the preservation of the race; which is similarly 
performed by all the members of the same more 
or less restricted group of animals; and which 
may be subject to subsequent modification under 
the guidance of experience. Such behaviour is, I 
conceive, a more or less complex organic or bio- 
logical response to a more or less complex group 
of stimuli of external and internal origin, and it 
is, as such, wholly dependent on how the organ- 
ism, and especially the nervous system and brain- 
centres, have been built through heredity, under 
that mode of racial preparation which we call 
biological evolution.” 
“Instinct,” Lloyd Morgan goes on to say, “is 
organic behaviour suffused with awareness.” 
Biologically considered, an instinctive act is no- 
thing but a reflex; psychologically considered, it 
is always something more, in so far as it affords 
data to the conscious experience which has its 
physical basis in the higher reaches of the nervous 
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627 
system. The book’s particular thesis, which 
applies primarily to vertebrate animals, is that 
instinctive behaviour, biologically considered, is 
dependent upon inherited dispositions within the 
lower brain-centres. In virtue of these inherited 
dispositions, the organism appropriately stimu- 
lated exhibits adaptive responses, and is subject 
to visceral disturbances. These afford new 
stimuli which in turn affect the lower brain-centres. 
But not these alone, for the initial sensory stimuli, 
those from the motor organs concerned in be- 
haviour, and those from the viscera, likewise 
stimulate the cortex of the cerebral hemispheres, 
with the functional activity of which experience is 
correlated. And this plays down upon the activi- 
ties of the lower nerve-centres, controlling them 
intelligently. 
“There are, of course, inherited dispositions in 
the cortical centres also, which determine mental 
tendencies. These may be called innate, reserving 
the narrower term instinctive for behaviour of a 
specific congenital type, dependent on purely bio- 
logical conditions, nowise guided by conscious 
experience, though affording data for the life of 
consciousness.” 
Instinctive behaviour is determined by the 
subtly compounded reflex actions of the lower 
centres; it is due to the integrative action 
of these centres; it differs from compound reflex 
actions (in the ordinary acceptation) in being 
the outcome of a more complicated coordination. 
A decerebrate animal may exhibit instinctive be- 
haviour, but, it is pointed out, this fact does 
not contradict the view that in the intact animal 
orderly impulses due to performance of instinctive 
acts may reach the cortex and there generate 
experience. This experience may form the basis 
of subsequent cortical or intelligent modification 
of the instinct, as is continually happening. 
Besides its direct contributions to the theory 
of instinct, the book contains much that is of great 
value for the student of science and philosophy. 
Thus it emphasises from first to last the im- 
portant rule of method “that the more clearly 
we distinguish the scientific problem from the 
metaphysical problems the better it will be 
both for science and for metaphysics”; and 
another dominant idea is that “the history of the 
universe, so far as we are able to read it, is 
one continuous story, every episode in which is, 
if we may so phrase it, logically correlated with 
other episodes.” So that even the richness and 
complexity of conscious awareness in human life 
is the highest outcome of the logic of the world- 
story, developed ab intra, and not an alien in- 
sertion from without. Both these general ideas 
command our heartiest allegiance. 
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