The anatomy of plants with an idea of a philosophical history of plants, and several other lectures, read before the royal society / by Nehemjah Grew ...

CHAP. II. Of the Principles of Bodies.

AND first, by Principles, I mean Atomes, or certain Sorts of Atomes, or of the simplest of Bodies. For otherwise they would not be Principles; for a compounded Principle, in strict speaking, is a Con∣tradiction. Even as Fives, Threes, or Two's are not the Principles of Number, but Unites.

2. §. Whence, secondly, it follows, that they are also Indivisible. Not Mathematically; for the Atomes of every Prin∣ciple have their Dimensions. But Physically; and so, what is but one, cannot be made two. If it be asked, Whether a Stick cut with a Knife, be not of one, made two? I say, that a Stick, is not one Body, but many millions of Bodies; that is, of Atomes; not any one whereof is divided within it self, but only they are separated one from another, where the Knife forceth its way. As in the drawing of a mans Finger through a Heap of Corn; there is no Division made in any one Grain, but only a separation of them one from another, all remaining still in themselves entire. I say, therefore, that what is Physically one, is also most firm, and Indivisible, that is, Impenetrable: for Penetration is but the Separation, not the Division of Atomes.

3. §. Hence, thirdly, they are also Immutable. For that which cannot be divided, cannot be chang'd. So that of the whole World of Atomes, not any one hath ever suffer'd, or can suffer the least mu∣tation. Hereupon is grounded the Constancy of Causes and Effects. So that, in all Generations, it is not less certain, that the self same Prin∣ciple is still propagated from the same; than, that Man is from Man. Wherefore, compounded Bodies are generated; but Principles are not, but only propagated; that is, in every Generation, they pass, in them∣selves unaltered, from one Body, into another.

4. §. If Principles, or Atomes are all Immutable; it again follows. That they are of Divers Kinds. For one and the same Principle, or Kind of Atomes, will still make the Same Thing, and have the same Effect: so that all Generations would then be the Same. Wherefore, since they are Immutable, they must be Divers.

5. §. This Diversity, for the same reason, is not small, but very Numerous. For as the World, taken together, is Natures Shop; so the Principles of Things are her Tools, and her Materials. Wherefore, as it speaks the goodness of a Shop; so the Perfection of the Universe, That it is furnished with many Tools wherewith, and many Materials whereupon to work. And consequently, that Philosophy beareth best its own name; which doth not strain all to two or three Principles, like two or three

Bells in a Steeple, making a pitiful Chime: but tryeth to rise up to Natures own Number, and so to ring all the Changes in the World.

6. §. Yet doth not this vast Diversity take away the Regiment and Subordination of Principles. There being a certain lesser number of them, which either by their greater quantity, or other ways, have Rule and Dominion, in their several Orders, over all the rest. For where-ever the Subject is Multitude, Order is part of its Perfection. For Order is Proportion. And how can Nature be imagin'd to hold Propor∣tion in all things else, and not here? Wherefore, as certainly, as Or∣der and Government are in all the Parts of the Rational; so certainly, of the Material World. Whence it is, That although the Species of Principles be very numerous; yet the Principles called Galenical, Chy∣mical, or any others, which do any way fall under the notice of Sense, are notwithstanding reduceable to a smaller number: viz. according to the number of Predominant Principles in Nature; or, rather in this part of the Universe which is near and round about us. To the Power and Empire whereof, all other Principles do submit. Which Submission, is not the quitting of their own Nature; but only their appearance under the external Face or Habit of the said Predominant Principles.

7. §. As there can be no Order of Principles, without Diversity; so no Diversity, but what is originally made by these two ways; sc. by Size and Figure. By these they may be exceeding different: and all other Properties besides, whereby they differ, must be dependent upon these Two.

8. §. Nor therefore, can they be of any other Figures, than what are Regular. For Regularity, is a Similitude continu'd. Since there∣fore all kinds of Atomes are divers only by their Size and Figure; if the selfe same Size and Figure were not common to a certain number of Atomes, they could not be said to be of any one kind: and consequent∣ly, if there were no Similitude of Atomes, there could be no Distin∣ction of Principles.

9. §. Hence also, these two Modes of Atomes, viz. their Size and Figure, are the true, and only original Qualities of Atomes. That is, an Atome is such or such, because it is of such a certain Size and Fi∣gure.

10. §. Lastly, As these two Modes, taken severally, are the Qua∣lities of an Atome: so consider'd together, they are its Form. A sub∣stantial Form of a Body, being an unintelligible thing. I say of a Body; for although the Rational Soul be a substantial Form, yet is it the Form of a Man, and not of a Body. For the Form of a Body, we can conceive of no otherwise, than as of the Modification of a Body, or a Complexion of all the Modes of a Body. Which also agrees with that Definition of a Form, which amongst the Peripatetick Philosophers is well enough accepted, viz. Quod sit, Ratio ejus Essentiae, quae cuique Rei competit. Which Ratio, if it be referred to a Body, what is it, but the Modification of that Body? Having thus proposed a Summary of my Thoughts about Principles; I shall next proceed to shew what their Mixture is.