practical life until
such time as he should be better instructed. The laws of this
"provisional self-government" are embodied in four maxims, of which one
binds our philosopher to submit himself to the laws and religion in
which he was brought up; another, to act, on all those occasions which
call for action, promptly and according to the best of his judgment, and
to abide, without repining, by the result: a third rule is to seek
happiness in limiting his desires, rather than in attempting to satisfy
them; while the last is to make the search after truth the business of
his life.

Thus prepared to go on living while he doubted, Descartes proceeded to
face his doubts like a man. One thing was clear to him, he would not lie
to himself--would, under no penalties, say, "I am sure" of that of which
he was not sure; but would go on digging and delving until he came to
the solid adamant; or, at worst, made sure there was no adamant. As the
record of his progress tells us, he was obliged to confess that life is
full of delusions; that authority may err; that testimony may be false
or mistaken; that reason lands us in endless fallacies; that memory is
often as little trustworthy as hope; that the evidence of the very
senses may be misunderstood; that dreams are real as long as they last,
and that what we call reality may be a long and restless dream. Nay, it
is conceivable that some powerful and malicious being may find his
pleasure in deluding us, and in making us believe the thing which is
not, every moment of our lives. What, then, is certain? What even, if
such a being exists, is beyond the reach of his powers of delusion? Why,
the fact that the thought, the present consciousness, exists. Our
thoughts may be delusive, but they cannot be fictitious. As thoughts,
they are real and existent, and the cleverest deceiver cannot make them
otherwise.

Thus, thought is existence. More than that, so far as we are concerned,
existence is thought, all our conceptions of existence being some kind
or other of thought. Do not for a moment suppose that these are mere
paradoxes or subtleties. A little reflection upon the commonest facts
proves them to be irrefragable truths. For example, I take up a marble,
and I find it to be a red, round, hard, single body. We call the
redness, the roundness, the hardness, and the singleness, "qualities" of
the marble; and it sounds, at first, the height of absurdity to say that
all these qualities are