nceive my self able to
deduce them from those first Truths which I have before discovered: But
that I would not expresly do it to crosse certain spirits, who imagine
that they know in a day al what another may have thought in twenty
yeers, as soon as he hath told them but two or three words; and who are
so much the more subject to erre, and less capable of the Truth, (as
they are more quick and penetrating) from taking occasion of erecting
some extravagant Philosophy on what they may beleeve to be my
Principles, and lest the fault should be attributed to me. For as for
those opinions which are wholly mine, I excuse them not as being new,
because that if the reasons of them be seriously considered, I assure my
self, they will be found so plain, and so agreeable to common sense,
that they will seem less extraordinary and strange then any other which
may be held on the same Subjects. Neither do I boast that I am the first
Inventor of any of them; but of this indeed, that I never admitted any
of them, neither because they had, or had not been said by others, but
only because Reason perswaded me to them.

If Mechanicks cannot so soon put in practise the Invention which is set
forth in the Opticks, I beleeve that therefore men ought not to condemn
it; forasmuch as skill and practice are necessary for the making and
compleating the Machines I have described; so that no circumstance
should be wanting. I should no less wonder if they should succeed at
first triall, then if a man should learn in a day to play excellently
well on a Lute, by having an exact piece set before him. And if I write
in French, which is the language of my Country, rather then in Latin,
which is that of my Tutors, 'tis because I hope such who use their meer
naturall reason, wil better judge of my opinions, then those who only
beleeve in old Books. And for those who joyn a right understanding with
study, (who I only wish for my Judges) I assure my self, they will not
be so partiall to the Latin, as to refuse to read my reasons because I
expresse them in a vulgar tongue.

To conclude, I will not speak here in particular of the progresse I
hoped to make hereafter in Learning; Nor engage my self by any promise
to the Publick, which I am not certain to perform. But I shall onely
say, That I am resolved to employ the remainder of my life in no other
thing but the study to acquire some such knowledge of Nature as may
furnish us with more certain rules in Physick