of God; of this idea I cannot be the
author, for it represents something much greater than I, and its cause
must be as great as the reality it represents. In other words, nothing
less than God can be the cause of the idea of God which I find in me,
and, hence, I may infer that God exists.

Where did Descartes get this notion that every idea must have a cause
which contains as much external reality as the idea does represented
reality? How does he prove his assumption? He simply appeals to what
he calls "the natural light," which is for him a source of all sorts of
information which cannot be derived from experience. This "natural
light" furnishes him with a vast number of "eternal truths", these he
has not brought under the sickle of his sweeping doubt, and these help
him to build up again the world he has overthrown, beginning with the
one indubitable fact discussed above.

To the men of a later time many of Descartes' eternal truths are simply
inherited philosophical prejudices, the results of the reflections of
earlier thinkers, and in sad need of revision. I shall not criticise
them in detail. The important point for us to notice is that we have
here a type of philosophy which depends upon truths revealed by the
reason, independently of experience, to carry one beyond the sphere of
experience.

I again remind the reader that there are all sorts of rationalists, in
the philosophical sense of the word. Some trust the power of the
unaided reason without reserve. Thus Spinoza, the pantheist, made the
magnificent but misguided attempt to deduce the whole system of things
physical and things mental from what he called the attributes of God,
Extension and Thought.

On the other hand, one may be a good deal of an empiricist, and yet
something of a rationalist, too. Thus Professor Strong, in his recent
brilliant book, "Why the Mind has a Body," maintains that we know
intuitively that other minds than our own exist; know it without
gathering our information from experience, and without having to
establish the fact in any way. This seems, at least, akin to the
doctrine of the "natural light," and yet no one can say that Professor
Strong does not, in general, believe in a philosophy of observation and
experiment.

61. EMPIRICISM.--I suppose every one who has done some reading in the
history of philosophy will, if his mother tongue be English, think of
the name of John Locke when empiricism is mentioned.

Locke