ve us. The very existence of the
conscious self, the _cogito, ergo sum_, which is the first of all
truths and therefore prior in certitude to the existence of God, is
believed only because of the clearness and distinctness with which we
apprehend it. How then, they argued, could God's truthfulness be our
security for a principle which we must use in order to prove the being
of God? The answer of Descartes is somewhat lame. We cannot doubt any
self-evident principle, or even any truth based on a self-evident
principle, when we are directly contemplating it in all the necessity
of its evidence; it is only when we forget or turn away from this
evidence, and begin to think of the possibility of a deceitful God,
that a doubt arises which cannot be removed except by the conviction
that God is true.[5] It can scarcely be said that this is a _dignus
vindice nodus_, or that God can fitly appear as a kind of second-best
resource to the forgetful spirit that has lost its direct hold on
truth and its faith in itself. God, truth, and the human spirit are
thus conceived as having merely external and accidental relations with
each other. What Descartes, however, is really expressing in this
exoteric way is simply that beneath and beyond all particular truths
lies the great general truth of the unity of thought and existence. In
contemplating particular truth, we may not consciously relate it to
this unity, but when we have to defend ourselves against scepticism we
are forced to realize this relation. The ultimate answer to any attack
upon a special aspect or element of truth must be to show that the
fate of truth itself, the very possibility of knowledge, is involved
in the rejection of it, and that we cannot doubt it without doubting
reason itself. But to doubt reason is, in the language of Descartes,
to doubt the truthfulness of God, for, in his view, the idea of God is
involved in the very constitution of reason. Taken in this way then,
the import of Descartes's answer is, that the consciousness of self,
like every other particular truth, is not at first seen to rest on the
consciousness of God, but that when we realize what it means we see
that it does so rest. But if this be so, then in making the
consciousness of self his first principle of knowledge, Descartes has
stopped short of the truth. It can only be the first principle if it
is understood, not as the con