Man thinks, he feels, and he wills: these are the three great functions
of the spiritual life. Let us inquire what, without God, would become,
first, of thought, which is the instrument of all knowledge; next; of
the conscience, which is the law of the will; then of the heart, which
is the organ of the feelings. We will begin with thought.

Let us go back to the origin of modern philosophy. The labors of
Descartes will make us acquainted, under the form clearest for us, with
a current of lofty thoughts which does honor to ancient civilization,
and which has come down to us through the writings of Plato and St.
Augustine. We have seen that Descartes deceived himself, when he thought
to separate himself altogether from tradition, and forgot the while how
intimately men's minds are bound together in a common possession of
truth. He was mistaken, because he confounded the idea, natural to the
human mind, of an infinite reason, with the full idea of the Creator; so
attributing to the efforts of his own philosophy that gift of truth
which he had received from the Christian tradition. But, having so far
recognized his error, listen now to this great man, and judge if he were
again mistaken in those thoughts of his which I am about to reproduce to
you.

Descartes strives hard to doubt of all things, persuaded that truth will
resist his efforts, and come forth triumphant from the trial. He doubts
of what he has heard in the schools: his masters may have led him into
error. He doubts of the evidence of his senses: his senses deceive him
in the visions of the night; what if he were always dreaming, and if his
waking hours were but another sleep with other dreams! He will doubt
even of the certainty of reason: what if the reason were a warped and