236 Mr. J. J. Woodward on the Modern 
the Greek conception of the threefold Psyche ‘ appears to be 
justified by the light of the science of our own day” *. 
For myself I must confess at once that I am quite unable 
to join either of these opposing camps as a partisan. I cannot 
accept the more strictly vitalistic views, because I am com- 
pelled continually to recognize the operation of purely che- 
mical and physical forces in living beings. On the other 
hand, there are whole groups of phenomena characteristic of 
living beings and peculiar to them of which the chemico- 
physical hypothesis offers no intelligible explanation. 
From this point of view the various processes and functions 
of living beings may indeed be divided into two classes, of 
which the first may be regarded with more or less certainty 
as the special results, under special conditions, of the very 
same forces that operate in the inorganic world; while the 
second, to which alone I would apply the term vital, are not 
merely in every respect peculiar to living beings, and hitherto 
utterly inexplicable by the laws of chemistry and physics, but 
are so different in character from the phenomena of the inor- 
ganic world, that it does not seem rational to attempt to 
explain them by these laws. 
Let me refer briefly to the processes and functions belonging 
to the first class. Here I place all those more strictly chemical 
processes by which, within the very substance of vegetable 
protoplasm, inorganic elements are combined into organic 
matter, as well as those which produce all the various subse- 
quent transformations, whether in plants or animals, of the 
organic matter thus prepared. This general conception in- 
cludes of course, in the case of the higher animals, all the 
chemical phases of the processes of digestion, assimilation, 
and tissue-metamorphosis or metabolism, including secretion 
and excretion; in the case of the lower animals and plants, 
so much of these several functions as belongs to each species. 
Now please to understand that when I say I recognize all 
the chemical phases of these processes to be the results of the 
ordinary chemical laws, I do not entertain any mental reserva- 
tion with regard to the unrestricted application of these laws. 
I cannot for a moment agree with those physiologists who 
have imagined the vital principle to thwart or interfere with 
or counteract these laws in any way. I know indeed that we 
are far from being as thoroughly acquainted as we may by and 
by hope to be with the chemical phenomena of living beings ; 
that many of the questions are very difficult, so that as yet, 
with all our labour, we have obtained but partial or even con- 
tradictory results; but I find in this only a reason for further 
* St. George Mivart, ‘The Cat’ (London, 1881), p. 387, 
