ation in function which follows on a variation in structure,
may be enormously greater than the variation of the structure, then, you
see, the objection falls to the ground.

Take a couple of watches--made by the same maker, and as completely
alike as possible; set them upon the table, and the function of
each--which is its rate of going--will be performed in the same manner,
and you shall be able to distinguish no difference between them; but let
me take a pair of pincers, and if my hand is steady enough to do it,
let me just lightly crush together the bearings of the balance-wheel, or
force to a slightly different angle the teeth of the escapement of one
of them, and of course you know the immediate result will be that
the watch, so treated, from that moment will cease to go. But what
proportion is there between the structural alteration and the functional
result? Is it not perfectly obvious that the alteration is of the
minutest kind, yet that slight as it is, it has produced an infinite
difference in the performance of the functions of these two instruments?

Well, now, apply that to the present question. What is it that
constitutes and makes man what he is? What is it but his power
of language--that language giving him the means of recording
his experience--making every generation somewhat wiser than its
predecessor,--more in accordance with the established order of the
universe?

What is it but this power of speech, of recording experience, which
enables men to be men--looking before and after and, in some dim
sense, understanding the working of this wondrous universe--and which
distinguishes man from the whole of the brute world? I say that this
functional difference is vast, unfathomable, and truly infinite in
its consequences; and I say at the same time, that it may depend upon
structural differences which shall be absolutely inappreciable to us
with our present means of investigation. What is this very speech that
we are talking about? I am speaking to you at this moment, but if you
were to alter, in the minutest degree, the proportion of the nervous
forces now active in the two nerves which supply the muscles of my
glottis, I should become suddenly dumb. The voice is produced only so
long as the vocal chords are parallel; and these are parallel only so
long as certain muscles contract with exact equality; and that again
depends on the equality of action of those two nerves I spoke of. So
that a change of t