_MADAM,_
I am reading now the works of that Famous and most Renowned _Author,
Des Cartes,_ out of which I intend to pick out onely those discourses
which I like best, and not to examine his opinions, as they go along
from the beginning to the end of his books; And in order to this, I
have chosen in the first place, his discourse of motion, and do not
assent to his opinion,[1] when he defines _Motion to be onely a Mode
of a thing, and not the thing or body it selfe_; for, in my opinion,
there can be no abstraction made of motion from body, neither really,
nor in the manner of our conception, for how can I conceive that
which is not, nor cannot be in nature, that is, to conceive motion
without body? Wherefore Motion is but one thing with body, without
any separation or abstraction soever. Neither doth it agree with my
reason, that[2] _one body can give or transferr motion into another
body; and as much motion it gives or transfers into that body, as
much loses it: As for example, in two hard bodies thrown against one
another, where one, that is thrown with greater force, takes the other
along with it, and loses as much motion as it gives it._ For how
can motion, being no substance, but onely a mode, quit one body, and
pass into another? One body may either occasion, or imitate anothers
motion, but it can neither give nor take away what belongs to its own
or another bodies substance, no more then matter can quit its nature
from being matter; and therefore my opinion is, that if motion doth
go out of one body into another, then substance goes too; for motion,
and substance or body, as afore-mentioned, are all one thing, and
then all bodies that receive motion from other bodies, must needs
increase in their substance and quantity, and those bodies which impart
or transferr motion, must decrease as much as they increase: Truly,
_Madam_, that neither Motion nor Figure should subsist by themselves,
and yet be transferable into other bodies, is very strange, and as much
as to prove them to be nothing, and yet to say they are something. The
like may be said of all others, which they call accidents, as skill,
learning, knowledge, &c. saying, they are no bodies, because they
have no extension, but inherent in bodies or substances as in their
subjects; for although the body may subsist without them, yet they
being always with the body, body and they are all one thing: And so is
power and body, for body cannot quit power, nor power the body, being
all one thing. But to return to Motion, my opinion is, That all matter
is partly animate, and partly inanimate, and all matter is moving and
moved, and that there is no part of Nature that hath not life and
knowledg, for there is no Part that has not a comixture of animate and
inanimate matter; and though the inanimate matter has no motion, nor
life and knowledg of it self, as the animate has, nevertheless being
both so closely joyned and commixed as in one body, the inanimate
moves as well as the animate, although not in the same manner; for the
animate moves of it self, and the inanimate moves by the help of the
animate, and thus the animate is moving and the inanimate moved; not
that the animate matter transfers, infuses, or communicates its own
motion to the inanimate; for this is impossible, by reason it cannot
part with its own nature, nor alter the nature of inanimate matter,
but each retains its own nature; for the inanimate matter remains
inanimate, that is, without self-motion, and the animate loses nothing
of its self-motion, which otherwise it would, if it should impart or
transferr its motion into the inanimate matter; but onely as I said
heretofore, the inanimate works or moves with the animate, because of
their close union and commixture; for the animate forces or causes
the inanimate matter to work with her; and thus one is moving, the
other moved, and consequently there is life and knowledg in all parts
of nature, by reason in all parts of nature there is a commixture of
animate and inanimate matter: and this Life and Knowledg is sense and
reason, or sensitive and rational corporeal motions, which are all one
thing with animate matter without any distinction or abstraction, and
can no more quit matter, then matter can quit motion. Wherefore every
creature being composed of this commixture of animate and inanimate
matter, has also selfe-motion, that is life and knowledg, sense and
reason, so that no part hath need to give or receive motion to or from
another part; although it may be an occasion of such a manner of motion
to another part, and cause it to move thus or thus: as for example,
A Watch-maker doth not give the watch its motion, but he is onely the
occasion, that the watch moves after that manner, for the motion of the
watch is the watches own motion, inherent in those parts ever since
that matter was, and if the watch ceases to move after such a manner or
way, that manner or way of motion is never the less in those parts of
matter, the watch is made of, and if several other figures should be
made of that matter, the power of moving in the said manner or mode,
would yet still remain in all those parts of matter as long as they are
body, and have motion in them. Wherefore one body may occasion another
body to move so or so, but not give it any motion, but every body
(though occasioned by another, to move in such a way) moves by its own
natural motion; for self-motion is the very nature of animate matter,
and is as much in hard, as in fluid bodies, although your _Author_
denies it, saying,[3] _The nature of fluid bodies consists in the
motion of those little insensible parts into which they are divided,
and the nature of hard bodies, when those little particles joyned
closely together, do rest_; for there is no rest in nature; wherefore
if there were a World of Gold, and a World of Air, I do verily believe,
that the World of Gold would be as much interiously active, as the
World of Air exteriously; for Natures motions are not all external or
perceptible by our senses, neither are they all circular, or onely of
one sort, but there is an infinite change and variety of motions; for
though I say in my Philosophical opinions,[4] _As there is but one
onely Matter, so there is but one onely Motion_; yet I do not mean,
there is but one particular sort of motions, as either circular, or
straight, or the like, but that the nature of motion is one and the
same, simple and intire in it self, that is, it is meer motion, or
nothing else but corporeal motion; and that as there are infinite
divisions or parts of matter, so there are infinite changes and
varieties of motions, which is the reason that I call motion as well
infinite as matter; first that matter and motion are but one thing, and
if matter be infinite, motion must be so too; and secondly, that motion
is infinite in its changes and variations, as matter is in its parts.
And thus much of motion for this time; I add no more, but rest,
Madam,
_Your faithful Friend,_
_and Servant._
[1] _Philos. p._ 2. _Art._ 25.
[2] _Art._ 40.
[3] _Philos. part._ 2. _a._ 54.
[4] _Part._ 1. _c._ 5.