of most human knowledge, proceeded to dig away the accumulated drift and
sand of ages in quest of any clay or rock there might be below, the
first indubitable verity he came to was thought, about whose reality
there could, as already explained, be no possibility of doubt, inasmuch
as any doubt concerning it, being itself thought, would be but an
additional proof of it. On the bit of firm ground thus thoroughly
tested, he proceeded to place a formula not less carefully verified, his
famous 'Cogito, ergo sum'--'I think, therefore I am.' By many of his
followers, however, this second verification of his is deemed to be by
no means so satisfactory as it was by himself, Professor Huxley more
especially taking vehement, though, as I make bold to add, somewhat
gratuitous, exception to every single word of the most celebrated of
Cartesian formulae. No doubt the premiss of the formula assumes the
conclusion, but it likewise includes as well as assumes it. No doubt,
since 'I think' is but another way of saying 'I am thinking,' to say
that 'I think' is to assume that 'I am;' nay, the same thing is equally
assumed by the mere introduction of the pronoun 'I.' But Descartes was
fully warranted in taking for granted the truth of his conclusion. For
by previously showing incontestably that thought and consciousness are
real existences, he had completely proved the premiss wherein his
conclusion is included. What though, as Professor Huxley suggests,
'thought' may possibly 'be self-existent,' 'or a given thought the
result of its antecedent thought, or of some external power'? Be thought
what else it may, it must needs be, also, either an affection or an
operation; if not performed, it must be felt; there must needs be,
therefore, something by which it is either performed or felt, and that
something cannot possibly be other than a thinking and conscious thing.
As surely as thought is, so surely must there be a thinker. This is, in
substance, affirmed even by many who deny it in terms, and Hume, in
particular, when saying, as he somewhere does, that 'all we are
conscious of is a series of perceptions,' denies and affirms it at one
and the same time. For how can there be perception without a percipient?
or how consciousness without a conscious entity? or how can that entity
be conscious of feeling without being simultaneously conscious that it
is itself which feels, without knowing, consequently, that it has a
self, or without being warra