nothing that did not appear to me more clear and certain than the
demonstrations of the geometers had formerly appeared; and yet I venture
to state that not only have I found means to satisfy myself in a short
time on all the principal difficulties which are usually treated of in
philosophy, but I have also observed certain laws established in nature by
God in such a manner, and of which he has impressed on our minds such
notions, that after we have reflected sufficiently upon these, we cannot
doubt that they are accurately observed in all that exists or takes place
in the world and farther, by considering the concatenation of these laws,
it appears to me that I have discovered many truths more useful and more
important than all I had before learned, or even had expected to learn.

But because I have essayed to expound the chief of these discoveries in a
treatise which certain considerations prevent me from publishing, I cannot
make the results known more conveniently than by here giving a summary of
the contents of this treatise.  It was my design to comprise in it all
that, before I set myself to write it, I thought I knew of the nature of
material objects.  But like the painters who, finding themselves unable to
represent equally well on a plain surface all the different faces of a
solid body, select one of the chief, on which alone they make the light
fall, and throwing the rest into the shade, allow them to appear only in
so far as they can be seen while looking at the principal one; so, fearing
lest I should not be able to compense in my discourse all that was in my
mind, I resolved to expound singly, though at considerable length, my
opinions regarding light; then to take the opportunity of adding something
on the sun and the fixed stars, since light almost wholly proceeds from
them; on the heavens since they transmit it; on the planets, comets, and
earth, since they reflect it; and particularly on all the bodies that are
upon the earth, since they are either colored, or transparent, or
luminous; and finally on man, since he is the spectator of these objects.
Further, to enable me to cast this variety of subjects somewhat into the
shade, and to express my judgment regarding them with greater freedom,
without being necessitated to adopt or refute the opinions of the learned,
I resolved to leave all the people here to their disputes, and to speak
only of what would happen in a new world, if God were now to create
somewhere in the imaginary spaces matter sufficient to compose one, and
were to agitate variously and confusedly the different parts of this
matter, so that there resulted a chaos as disordered as the poets ever
feigned, and after that did nothing more than lend his ordinary
concurrence to nature, and allow her to act in accordance with the laws
which he had established.  On this supposition, I, in the first place,
described this matter, and essayed to represent it in such a manner that
to my mind there can be nothing clearer and more intelligible, except what
has been recently said regarding God and the soul; for I even expressly
supposed that it possessed none of those forms or qualities which are so
debated in the schools, nor in general anything the knowledge of which is
not so natural to our minds that no one can so much as imagine himself
ignorant of it.  Besides, I have pointed out what are the laws of nature;
and, with no other principle upon which to found my reasonings except the
infinite perfection of God, I endeavored to demonstrate all those about
which there could be any room for doubt, and to prove that they are such,
that even if God had created more worlds, there could have been none in
which these laws were not observed.  Thereafter, I showed how the greatest
part of the matter of this chaos must, in accordance with these laws,
dispose and arrange itself in such a way as to present the appearance of
heavens; how in the meantime some of its parts must compose an earth and
some planets and comets, and others a sun and fixed stars.  And, making a
digression at this stage on the subject of light, I expounded at
considerable length what the nature of that light must be which is found
in the sun and the stars, and how thence in an instant of time it
traverses the immense spaces of the heavens, and how from the planets and
comets it is reflected towards the earth.  To this I likewise added much
respecting the substance, the situation, the motions, and all the
different qualities of these heavens and stars; so that I thought I had
said enough respecting them to show that there is nothing observable in
the heavens or stars of our system that must not, or at least may not
appear precisely alike in those of the system which I described.  I came
next to speak of the earth in particular, and to show how, even though I
had expressly supposed that God had given no weight to the matter of which
it is composed, this should not prevent all its parts from tending exactly
to its center; how with water and air on its surface, the disposition of
the heavens and heavenly bodies, more especially of the moon, must cause a
flow and ebb, like in all its circumstances to that observed in our seas,
as also a certain current both of water and air from east to west, such as
is likewise observed between the tropics; how the mountains, seas,
fountains, and rivers might naturally be formed in it, and the metals
produced in the mines, and the plants grow in the fields and in general,
how all the bodies which are commonly denominated mixed or composite might
be generated and, among other things in the discoveries alluded to
inasmuch as besides the stars, I knew nothing except fire which produces
light, I spared no pains to set forth all that pertains to its nature, --
the manner of its production and support, and to explain how heat is
sometimes found without light, and light without heat; to show how it can
induce various colors upon different bodies and other diverse qualities;
how it reduces some to a liquid state and hardens others; how it can
consume almost all bodies, or convert them into ashes and smoke; and
finally, how from these ashes, by the mere intensity of its action, it
forms glass:  for as this transmutation of ashes into glass appeared to me
as wonderful as any other in nature, I took a special pleasure in
describing it.  I was not, however, disposed, from these circumstances, to
conclude that this world had been created in the manner I described; for
it is much more likely that God made it at the first such as it was to be.
But this is certain, and an opinion commonly received among theologians,
that the action by which he now sustains it is the same with that by which
he originally created it; so that even although he had from the beginning
given it no other form than that of chaos, provided only he had
established certain laws of nature, and had lent it his concurrence to
enable it to act as it is wont to do, it may be believed, without
discredit to the miracle of creation, that, in this way alone, things
purely material might, in course of time, have become such as we observe