244 
satisfied with that account of the origination of an event which simply refers 
it to another event immediately preceding ? Can the human mind, in its 
self-impelled search for causes, stop short of anything other than reality, 
endowed with powers enabling it to produce certain effects '? An examination 
of our judgments concerning the realities presented to us, reveals the fact 
that we are compelled to think each of them as possessing a given consti- 
tution, as endowed with certain “ qualities and “ powers.” These judgments 
we must accept as the starting points of thought ; their validity cannot by 
us be determined in the light of higher truths ; to us they are ultimate. 
Turning to the world of matter, let us begin with the atoms themselves— 
what, by the very laws of our intelligence, are we compelled to think about 
them ? First, we think that each atom possesses certain “ qualities.” These 
all have relation to space, and constitute the “primary” qualities of the 
metaphysician. Second, we think the atoms to possess also certain 
“ powers,” whose existence we apprehend not immediately as we do that of 
the qualities, but only mediately or through their effects. Now, since each 
atom has both qualities and powers, the theory that matter is indestructible, 
embraces two things : — 
(1.) The conservation or persistence of material qualities. 
(2.) The conservation or persistence of material powers. 
To regard these two doctrines as separable is unphilosophical ; they are but 
different aspects of the one truth concerning the indestructibility of matter 
by human agents. That this is so, is evident from the fact that is impossible, 
even in imagination, to separate the powers from the qualities, as associated 
together in the most elementary form, of material existence. In this 
connection Faraday’s words are very important and significant. He says : 
“ A particle of oxygen is ever a particle of oxygen ; nothing can in the least 
wear it. If it enter into combination, and disappear as oxygen ; if it pass 
through a thousand combinations — animal, vegetable, and mineral ; if it lie 
hid for a thousand years, and then be evolved, it is oxygen with its first 
qualities neither more nor less. It has all its original force, and only that.” 
To-night, Mr. Brooke has told us that “ in cases of percussion, the energy of 
a striking body may be more or less imparted to the body struck.” But is 
not this statement wholly inconsistent with the doctrine of the indestructi- 
bility of matter ? If, when an atom of oxygen exerts one or more of its 
powers, there is a transference of energy to some other reality, does it not 
then cease to be a particle of oxygen ? “ Energy,” says Mr. Brooke, “ was 
first defined, by Thomas Young, to be “ the power of doing work,” and this 
definition does not appear to require any amendment.” Now, if by “ work” 
is here meant the mere displacement of matter, either molecularly or 
in mass, the distinction between force and energy is not a valid one. Take 
any power— mental, vital, or material : we find that we are able to think it 
either as unexerted or as exerted ; in other words, as power “ at rest,” or 
power “ in action.” To denote the latter, philosophers have employed the term 
energy ; so that energy is not the power of doing work, but power doing work, 
power in work (ev epyov). But this is not the only case in which we think 
