Philosophical Conceptions of Life. 257 
together of the atoms, has been boldly revived of late years, 
and transmuted into a form more plausible to modern thought, 
although just as unsupported by any actual knowledge of 
facts. 
No one has done this more boldly or more cleverly than 
Mr. Herbert Spencer has done in his ‘ First Principles,’ and 
of course you are all familiar with the ingenious argument, 
in favour of this view, which runs through that masterly 
work. It would be, from many points of view, profitable, 
but it would be a very laborious task, to attempt the critical 
discussion of his argument. It must suffice, for my present 
purpose, to point out that two of the fundamental assumptions 
upon which that argument is based are wholly undemonstrated. 
The first assumption is, that mind is itself a force*; the 
second, that mind cannot be conscious of itself, but only of 
the external worldT. 
If I could bring myself to believe that mind is, in any 
proper sense of the word, a force, and that such popular meta- 
phorical expressions as mental force or mental energy accu- 
rately described the phenomena, I should certainly expect to 
find at least some shadow of proof for Mr. Herbert Spencer’s 
assertion that mental operations fall within the great gene- 
ralization of the correlation and equivalence of the forces. 
On the contrary, however, you will find, on reading his lucid 
periods, that his whole argument relates to those physical 
conditions in the organs of sense and in the muscular and 
nervous systems which are the antecedents of perception— 
which are, in fact, the things really perceived—and in no 
sense constitute the perceiving mind. Between strictly 
mental phenomena and the physical forces no one has as yet 
even attempted to establish a numerical equivalent; nay, more, 
the correlation of thought with the physical forces is not 
only undemonstrated, it is utterly unthinkable. You can con- 
ceive several different ways, it matters not whether true or 
false, in which the motions we know as heat might be con- 
verted into those we know as light, and so on with the other 
physical forces; but you cannot represent mentally any 
intelligible scheme by which any of the physical forces can 
be converted into the simplest or most elementary thought. 
As to the question of self-consciousness, it seems as if the 
great philosopher were reasoning in a circle. He first assumes 
that the fundamental condition of all consciousness is the 
antithesis between subject and object,—which is true only 
* Herbert Spencer, ‘ First Principles,’ Amer. Ud. New York, 1864, 
p. 274. 
+ Id. op, cit. p. 65 et seg. 
