86 SECTIONAL ADDRESSES 
de la Méthode, and it has been for long a guiding principle of research 
in the physiological study of functions and behaviour. 
Let me give you a modern example by quoting a passage from Pavlov’s 
book on Conditioned Reflexes, published in 1927. ‘ Our starting point,’ 
he writes, ‘ has been Descartes’ idea of the nervous reflex. ‘This is a 
genuine scientific conception, since it implies necessity. It may be 
summed up as follows : an external or internal stimulus falls on some one 
or other nervous receptor and gives rise to a nervous impulse ; this 
nervous impulse is transmitted along nerve fibres to the central nervous 
system, and here, on account of existing nervous connections, it gives 
rise to a fresh impulse which passes along outgoing nerve fibres to the 
active organ, where it excites a special activity of the cellular structures. 
Thus a stimulus appears to be connected of necessity with a definite 
response as cause with effect’ (p. 7). We could not wish for a clearer 
statement of the underlying assumptions of the stimulus-response (S-R) 
theory of animal behaviour, nor for a clearer acknowledgment of. its 
source. 
It was Descartes, then, who imposed upon European thought for at 
least two centuries, and upon biology for much longer, that ‘ bifurcation ’ 
of Nature into matter and mind which has raised so many insoluble 
problems for philosophy, and diverted biology from its true method. As 
to its effect on philosophy, let me quote a great modern philosopher, 
Prof. A. N. Whitehead, who writes: ‘ The seventeenth century had 
finally produced a scheme of scientific thought framed by mathematicians, 
for the use of mathematicians. . . . The enormous success of the scientific 
abstractions, yielding on the one hand matter with its simple location in 
space and time, on the other hand mind, perceiving, suffering, reasoning, 
but not interfering, has foisted on to philosophy the task of accepting 
them as the most concrete rendering of fact. Thereby, modern philosophy 
has been ruined. There are the dualists, who accept matter and mind as 
on equal basis, and the two varieties of monists, those who put mind 
inside matter, and those who put matter inside mind. But this juggling 
with abstractions can never overcome the inherent confusion introduced 
by the ascription of misplaced concreteness to the scientific scheme of the 
seventeenth century.’ 3 
Actually, instead of being the most concrete of realities, both matter 
and mind are highly abstract concepts, the product of the reflective 
intelligence working upon the data of immediate experience. 
There is given in individual experience only the perceiving subject 
and his objective world. This dualism does not correspond, is not 
synonymous with, the dualism of matter and mind. Subjective experi- 
ence as we know it directly is a function of organism, not of pure mind ; 
objective experience is a relation between organism and other processes 
or events. The concept of matter is arrived at by abstracting from the 
data of sense, by leaving out the ‘ secondary qualities ’ such as colour, 
smell and sound, and retaining the so-called ‘ primary qualities’ of 
a 
% Science and the Modern World, Cambridge, 1926, p. 70. 
