Philosophical Letters: or, modest Reflections upon some Opinions in Natural Philosophy. Duchess of Margaret Cavendish Newcastle
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 transferrs 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.
XXXI.
MADAM,
I observe your Author in his discourse of Place makes a difference[1] betwixt an Interior and Exterior place, and that according to this distinction, one body may be said to change, and not to change its place at the same time, and that one body may succeed into anothers place. But I am not of this opinion, for I believe not that there is any more place then body; as for example, Water being mix'd with Earth, the water doth not take the Earths place, but as their parts intermix, so do their places, and as their parts change, so do their places, so that there is no more place, then there is water and earth; the same may be said of Air and Water, or Air and Earth, or did they all mix together; for as their bodies join, so do their places, and as they are separated from each other, so are their places. Say a man travels a hundred miles, and so a hundred thousand paces; but yet this man has not been in a hundred thousand places, for he never had any other place but his own, he hath joined and separated himselfe from a hundred thousand, nay millions of parts, but he has left no places behind him. You will say, if he travel the same way back again, then he is said to travel thorow the same places. I answer, It may be the vulgar way of expression, or the common phrase; but to speak properly, after a Philosophical way, and according to the truth in nature, he cannot be said to go back again thorow the same places he went, because he left none behind him, or els all his way would be nothing but place after place, all the hundred miles along; besides if place should be taken so, as to express the joyning to the neerest bodies which compass him about, certainly he would never find his places again; for the air being fluid, changes or moves continually, and perchance the same parts of the air, which compassed him once, will never come near him again. But you may say, If a man be hurt, or hath some mischance in his body, so as to have a piece of flesh cut out, and new flesh growing there; then we say,