16 THE PRESIDENTIAL ADDRESS 
challenged. Some here will perhaps remember that in his Address 
to Section I, twenty-five years ago he described a philosophic stand- 
point which he has courageously maintained in many writings since. 
Dr. Haldane holds that to the enlightened biologist a living organism 
does not present a problem for analysis ; it is, gua organism, axio- 
matic. Its essential attributes are axiomatic; heredity, for example, 
is for biology not a problem but an axiom. ‘The problem of 
Physiology is not to obtain piecemeal physico-explanations of 
physiological processes ’ (I quote from the 1885 Address), ‘ but to 
discover by observation and experiment the relatedness to one 
another of all the details of structure and activity in each organism 
as expressions of its nature as one organism.’ I cannot pretend 
adequately to discuss these views here. They have often been 
discussed by others, not always perhaps with understanding. What 
is true in them is subtle, and I doubt if their author has ever found 
the right words in which to bring to most others a conviction of 
such truth. It is involved in a world outlook. What I think is 
scientifically faulty in Haldane’s teaching is the @ priori element 
which leads to bias in the face of evidence. The task he sets for 
the physiologist seems vague to most people, and he forgets that 
with good judgment a study of parts may lead to an intellectual 
synthesis of value. In 1885 he wrote: ‘That a meeting-point 
between Biology and Physical Science may at some time be found 
there is no reason for doubting. But we may confidently predict 
that if that meeting-point is found, and one of the two sciences 
is swallowed up, that one will not be Biology.’ He now claims 
indeed that biology has accomplished the heavy meal because 
physics has been compelled to deal no longer with Newtonian 
entities but, like the biologist, with organisms such as the atom 
proves to be. Is it not then enough for my present purpose to 
remark on the significance of the fact that not until certain atoms 
were found spontaneously splitting piecemeal into parts, and others 
were afterwards so split in the laboratory, did we really know any- 
thing about the atom as a whole. 
At this point, however, I will ask you not to suspect me of claiming 
that all the attributes of living systems or even the more obvious 
among them are necessarily based upon chemical organisation alone. 
I have already expressed my own belief that this organisation will 
account for one striking characteristic of every living cell—its ability, 
namely, to maintain a dynamic individuality in diverse environments. 
Living cells display other attributes even more characteristic of 
themselves ; they grow, multiply, inherit qualities and transmit 
them. Although to distinguish levels of organisation in such 
systems may be to abstract from reality it is not illogical to believe 
that such attributes as these are based upon organisation at a level 
