and reason, which has no
part in it, tries in vain to impugn them. The sceptics, who have only this
for their object, labour to no purpose. We know that we do not dream, and,
however impossible it is for us to prove it by reason, this inability
demonstrates only the weakness of our reason, but not, as they affirm, the
uncertainty of all our knowledge. For the knowledge of first principles, as
space, time, motion, number, is as sure as any of those which we get from
reasoning. And reason must trust these intuitions of the heart, and must
base them on every argument. (We have intuitive knowledge of the
tri-dimensional nature of space and of the infinity of number, and reason
then shows that there are no two square numbers one of which is double of
the other. Principles are intuited, propositions are inferred, all with
certainty, though in different ways.) And it is as useless and absurd for
reason to demand from the heart proofs of her first principles, before
admitting them, as it would be for the heart to demand from reason an
intuition of all demonstrated propositions before accepting them.
This inability ought, then, to serve only to humble reason, which would
judge all, but not to impugn our certainty, as if only reason were capable
of instructing us. Would to God, on the contrary, that we had never need of
it, an