know; And that for example a child
instructed in Arithmatick having made an addition according to his
rules, may be sure to have found, touching the sum he examined, all what
the wit of man could finde out. In a word the method which teacheth to
folow a right order, and exactly to enumerate all the circumstances of
what we seek, contains, whatsoever ascertains the rules of Arithmatick.

But that which pleas'd me most in this Method was the assurance I had,
wholly to use my reason, if not perfectly, at least as much as it was in
my power; Besides this, I perceived in the practice of it, my minde by
little and little accustom'd it self to conceive its objects more
clearly and distinctly; and having not subjected it to any particular
matter, I promised my self to apply it also as profitable to the
difficulties, of other sciences as I had to Algebra: Not that I
therefore durst at first undertake to examine all which might present
themselves, for that were contrary to the order it prescribes. But
having observ'd that all their principles were to be borrowed from
Philosophy, in which I had yet found none that were certain, I thought
it were needfull for me in the first place to endevor to establish some,
and that this being the most important thing in the world, wherein
precipitation and prevention were the most to be feared, I should not
undertake to performe it, till I had attain'd to a riper Age then XXIII.
which was then mine. Before I had formerly employed a long time in
preparing my self thereunto, aswel in rooting out of my minde all the
ill opinions I had before that time received, as in getting a stock of
experience to serve afterwards for the subject of my reasonings, and in
exercising my self always in the Method I had prescribed. That I might
the more and more confine my self therein.

PART. III.

But as it is not enough to pull down the house where we dwell, before we
begin to re-edify it, and to make provision of materials and architects,
or performe that office our selves; nor yet to have carefully laid the
design of it; but we must also have provided our selves of some other
place of abode during the time of the rebuilding: So that I might not
remain irresolute in my actions, while reason would oblige me to be so
in my judgments, and that I might continue to live the most happily I
could, I form'd for my own use in the interim a Moral, which consisted
but of three or four Maximes, which I shall comm