267 
of Edinburgh, Session 1864-65. 
so exactly ascertained — the force of gravitation ? It is invisible, 
— imponderable. All our words for it are but circumlocutions 
to express its phenomena or its effects. There are many kinds 
of force in nature — which we distinguish after the same fashion — 
according to their effects, or according to the forms of matter in 
which they become cognisable to us. But if we trace up our con- 
ceptions on the nature of force to their fountain-head, we shall pro- 
bably find that they are connected, more or less directly, with our 
own consciousness of living effort, — of that force which has its 
seat in our own vitality, and especially with that kind of it which 
can be called forth at the bidding of the will. If we can ever 
know anything of the nature of any force, it ought to be of this 
one. And yet the fact is that we know nothing. The vital forces 
which work in our organisation, work, for the most part, entirely 
independent of our will, and even of our consciousness. Those of 
them which are at the bidding of will are subject to it only through 
an elaborate machinery ; and if that machinery be damaged, we 
know too often, by sad experience, that their connection with the will 
is broken. If, then, we know nothing of that kind of force which is 
so near us, and with which our own intelligence is, so to speak, in 
such close alliance, much less can we know the ultimate nature of 
force in its other forms. I dwell on this because I think that both 
the aversion with which some men regard the idea of creation by 
Law, and the eagerness with which some others hail it, are founded 
on a notion, that when we have traced any given phenomena to 
what are called natural forces, we have traced them farther than 
we really have. We know nothing of the ultimate seat of force. 
Science, in the modern doctrine of the Conservation of Energy and 
Convertibility of Forces, is already getting something like a firm 
hold of the idea, that all kinds of force are but forms and mani- 
festations of some one central force, issuing from some one fountain- 
head of power. Sir John Herschel has not hesitated to say, that 
“it is but reasonable to regard the force of gravitation as the 
direct or indirect result of a consciousness, and a Will existing some- 
where.”* And even if we cannot assume that force, in all its forms, 
is due to the direct working of the Creator, at least let us not 
* Outlines of Astronomy. 3d ed. p. 265. 
