Then as to the analysis of the ancients and the algebra of the moderns,
besides that they embrace only matters highly abstract, and, to
appearance, of no use, the former is so exclusively restricted to the
consideration of figures, that it can exercise the understanding only on
condition of greatly fatiguing the imagination; and, in the latter, there
is so complete a subjection to certain rules and formulas, that there
results an art full of confusion and obscurity calculated to embarrass,
instead of a science fitted to cultivate the mind. By these considerations
I was induced to seek some other method which would comprise the
advantages of the three and be exempt from their defects. And as a
multitude of laws often only hampers justice, so that a state is best
governed when, with few laws, these are rigidly administered; in like
manner, instead of the great number of precepts of which logic is
composed, I believed that the four following would prove perfectly
sufficient for me, provided I took the firm and unwavering resolution
never in a single instance to fail in observing them.

The first was never to accept anything for true which I did not clearly know
to be such; that is to say, carefully to avoid precipitancy and prejudice,
and to comprise nothing more in my judgement than what was presented to
my mind so clearly and distinctly as to exclude all ground of doubt.

The second, to divide each of the difficulties under examination into as many
parts as possible, and as might be necessary for its adequate solution.

The third, to conduct my thoughts in such order that, by commencing with
objects the simplest and easiest to know, I might ascend by little and
little, and, as it were, step by step, to the knowledge of the more complex;
assigning in thought a certain order even to those objects which in their
own nature do not stand in a relation of antecedence and sequence.