ered as bright in mind as others. He was led to judge his
neighbor by himself, and to conclude that there existed no such certain
science as he had been taught to suppose.

Having ripened with years and experience, Descartes set about the task
of which I have spoken above, the task of sweeping away the whole body
of his opinions and of attempting a general and systematic
reconstruction. So important a work should be, he thought, approached
with circumspection; hence, he formulated certain Rules of Method.

"The first," he writes, "was never to accept anything for true which I
did not clearly know to be such; that is, carefully to avoid haste and
prejudice, and to include nothing more in my judgments than what was
presented to my mind so clearly and distinctly as to exclude all reason
for doubt."

Such was our philosopher's design, and such the spirit in which he set
about it. We have seen the result above. It is as if Descartes had
decided that a certain room full of people did not appear to be free
from suspicious characters, and had cleared out every one, afterwards
posting himself at the door to readmit only those who proved themselves
worthy. When we examine those who succeeded in passing muster, we
discover he has favored all his old friends. He simply _cannot_ doubt
them; are they not vouched for by the "natural light"? Nevertheless,
we must not forget that Descartes sifted his congregation with much
travail of spirit. He did try to be critical.

As for John Locke, he reveals in the "Epistle to the Reader," which
stands as a preface to the "Essay," the critical spirit in which his
work was taken up. "Were it fit to trouble thee," he writes, "with the
history of this Essay, I should tell thee, that five or six friends
meeting at my chamber, and discoursing on a subject very remote from
this, found themselves quickly at a stand, by the difficulties that
rose on every side. After we had a while puzzled ourselves, without
coming any nearer a resolution of those doubts which perplexed us, it
came into my thoughts, that we took a wrong course; and that before we
set ourselves upon inquiries of that nature, it was necessary to
examine our own abilities, and to see what objects our understandings
were, or were not, fitted to deal with."

This problem, proposed by himself to his little circle of friends,
Locke attacked with earnestness, and as a result he brought out many
years later the work which has since