30. Of Contraction and Dilation.
THere have been, and are still great disputes a∣mongst the Learned concerning Contraction and Extension of bodies; but if I were to decide their con∣troversie, I would ask first, Whether they did all agree in one principle? that is, whether their principle was purely natural, and not mixt with divine or supernatural things; for if they did not well apprehend one anothers meaning, or argued upon different principles, it would be but a folly to dispute, because it would be impos∣sible for them to agree. But concerning Contraction and Dilation, my opinion is, That there can be no Contraction nor Extension of a single part, by reason there is no such thing as a single or individeable part in Nature; for even that which the learned call an atome, although they make it a single body, yet being mate∣terial or corporeal, it must needs be divideable: Where∣fore Page 133 all Contraction and Dilation consists of parts as much as body doth, and there is no body that is not contractive and dilative, as well as it is divideable and composeable; for parts are, as it were, the effects of a body, by reason there is no body without parts; and contraction and extension are the effects of parts, and magnitude and place are the effects of contraction and extension; and all these are the effects of corporeal fi∣gurative self-motion, which I have more fully declared in several places of my Philosophical Works.
But some may say, It is impossible that a body can make it self bigger or less then by Nature it is? My answer is, I do not conceive what is meant by being little or great by Nature; for Nature is in a perpetual motion, and so are her parts, which do work, inter∣mix, join, divide and move according as Nature plea∣ses without any rest or intermission. Now if there be such changes of parts and motions, it is impossible that there can be any constant figure in Nature; I mean, so as not to have its changes of motions as well as the rest, although they be not all after the same manner; And if there can be no constant figure in Nature, there can neither be a constant littleness or greatness, nor a constant rarity or density, but all parts of Nature must change according to their motions; for as parts divide and compose, so are their figures; and since there are contracting and dilating motions, as well as there are of other sorts, there are also contracting and dilating Page 134 parts; and if there be contracting and dilating parts, then their magnitude changes accordingly; for mag∣nitude doth not barely consist in quantity, but in the ex∣tension of the parts of the body, and as the magnitude of a body is, so is place; so that place is larger, or less, according as the body contracts or dilates; for it is well to be observed, that it is not the interior figure of any part of Creature of Nature that alters by contraction or dilation; for example, Gold or Quicksilver is not changed from being Gold or Quicksilver when it is ra∣rified, but onely that figure puts it self into several po∣stures. Which proves, that the extension of a body is not made by an addition or intermixture of forraign parts, as composition; nor contraction, by a dimi∣nution of its own parts, as division; for dilation and composition, as also division and contraction, are dif∣ferent actions; the dilation of a body is an extension of its own parts, but composition is an addition of forreign parts; and contraction, although it makes the body less in magnitude, yet it loses nothing of its own parts: The truth is, as division and composition are natural corporeal motions, so are contraction and dilation; and as both composition and division belong to parts, so do contraction and dilation; for there can be no contracti∣on or dilation of a single part.