Philosophical Conceptions of Life. 235 
phenomena of the Psyche, as manifested by the human species, 
he openly and continually confesses the extent to which he 
relies upon the authority of Plato; and when the dicta of the 
master are such as to require a special effort of faith on the 
part of the disciple, he honestly exclaims, ‘‘ Plato indeed 
appears to be persuaded of this; as for me, whether it be so or 
not, I am unable to dispute the question with him” *. 
In like manner, did they venture to be as frank as Galen 
was, most of the modern biologists who have adopted the 
chemico-physical theory of life would, I presume, confess, 
“* As to this matter our opinions are derived from Mr. Herbert 
Spencer’s ‘ Principles of Biology;’ what are we that we should 
venture to dispute as to questions like these with him?” 
Nevertheless in striking contrast to this chemico-physical 
hypothesis of life, which is to be regarded as the fashionable 
faith of the hour, there still survives in many quarters, and 
especially among physicians, a disposition to regard indis- 
criminately almost all the phenomena of living beings as 
peculiar manifestations of a vital principle. So strong, indeed, 
is the faith of some of these modern vitalists, that they seem 
to shut their eyes to the evidence already in our possession 
as to the actual participation of known chemical and physical 
forces in the operations going on within living bodies, and 
appear almost to resent the willing aid that chemistry and 
ea afford to the physiological investigator of the present 
ay. 
Nay, further than this, in the inevitable reaction that is 
beginning to make itself felt against the avowed revival of 
the materialism of Epicurus and Lucretius—for we all know 
now that the chemico-physical hypothesis of life is not a new 
induction of modern science, but an ancient Greek speculation 
reappearing in modern petticoats—that other Greek specula- 
tion of the threefold Psyche, the doctrine taught by Plato and 
Aristotle, and which Galen accepted on their authority, the 
doctrine of a vegetable, an animal, and a rational soul, a 
human trinity coexisting in every human being, is once more 
rehabilitated and finding followers—likely, indeed, as I think, 
to obtain more followers than perhaps any of you yet suppose. 
And these followers are by no means confined to metaphysi- 
cians or churchmen; they can be found also already among 
the biologists. It is an English biologist of good repute and 
of no mean abilities who takes occasion, in a technical biolo- 
gical work published this very year, to express his belief that 
* Galen, ‘Quod animi mores corporis temperamenta sequantur,’ cap. 3 
(Kiihn’s edit. t. iv. p. 772). 
16* 
