with great Pride and little Reafon. Gilbert has best display'd the feveral Experiments of the Load-ftone. Harvey has reafon'd with the greatest Judgment upon the Progrefs of the Generation of Animals, and upon the Circulation of the Blood. Fromondus has written best of Meteors; Savot of Colours; Mersennus of Sounds and Harmony; Willis of the Brain, and its Parts; Grew of the Anatomy of Plants. Flud feems very deficient in good Senfe: He may be ftil'd the Paracelfus of Philofophers, as Paracelfus the Flud of Phyficians; these two Genius's feem little different in Complexion. Gaffendus has written very handfomely against Flud's Phyficks. Borellus is a good Geometrician and Naturalist, but without any metaphyfical Princi ples; which Defect renders his Pofitions very uncertain. Thomas Hobbes, in his Phyficks, has fhewn a Depth of Wit; but as he is the boldest and most through-pac'd Epicurean of thefe later Times, without any Mitigation, or Allay, he has reafon'd very abfurdly as to the Nature of the Understanding, and its principal Operati ons; which he refers wholly to the Fancy and Imagination. Boyle is a true and rational Genius, who has very much enrich'd natural Philofophy by his Experiments and Remarks, fuch as are always folid and well-grounded.

X.

But, after all, to do Juftice to our own Na tion, and to the Memory of Defcartes, we muft acknowledge, that his Syftem of Phyficks is one of the moft fubtile, and the most accom→ plish'd that have been publish'd by the Moderns; that he has fome very curious and very fine Conceptions; and that, upon a nearer View, his - Theory will appear to be more regular and confiftent than that of Galilei, or of the English

Authors.

A

Authors. We fhall likewife find, that he exceeds Gaffendus in Point of Novelty and Invention. In a Word, his Syftem is well digested, and put into an agreeable Order; his Method is entirely Geometrical, proceeding from Prin-. ciple to Principle, from Propofition to Propofi tion. But let us confider in what Refpects he is liable to Cenfure. His Principles of Nature, are Motion, Figure, and Extenfion; very little different from thofe of Democritus and Epicurus. There goes a pleasant Story, that Father Merfennus, who was his Refident at Paris, having declar'd in a Meeting of learned Men, that Defcartes, who had already establish'd a good Character by his Geometry, was upon a Project of Phyficks, in which be admitted a Vacuum, the Defign was fcouted by Robertval and others, who judg'd from hence, that it could contain nothing extraordinary. Upon which Father Merfennus writ to Defcartes, to let him know that a Vacuum was not modifh at Paris; and this oblig'd him to find out fome fort of Temperament, and fome way of compounding with the modern Naturalifts, whofe Approbation he much courted; and, in order to this, to admit the Plenum of Leucippus; and thus his Exclufion of a Vacuum was owing to a Principle of Politicks. But here Gaffendus put him under new Difficulties, giving him to understand, that without a Vacuum, his Principle of Motion would be abfurd and impoffible because nothing can move in an abfolute Plenum. Defcartes to remedy this Inconvenience, invented his fubtile Matter, which ferv'd him for a good Expedient in many Exigencies, and was a Salvo for the Doctrine either of a Vacuum or a Plenum, as he had Occafion to make ufe of them. But this Plenum, and this fubtile Matter being ad

1.

ded

ded only as a Shift, and in Compliance with the Humour of the Age, Defcartes's Syftem was left very weak and unguarded in the whole Doctrine of Motion, which is one of his main Principles: For he tells us, That all the Motion now in the World was created at the Beginning of Things, and that there's no new Motion produc'd, but the old communicated and tranfmitted from one Body to another; that the Impulsion of fubtile Matter is the Caufe of all Gravity or Levity in Bodies; that the Acceleration of heavy Bodies in their Motion towards the Center, proceeds from the fame Impulfion; that Heat is nothing but a Motion of the Particles of the Air, agitated by the fubtile Matter, which is the Fac-totum of the Cartefian Phyficks; that the Vegetation of Plants, and Generation of Animals, are caus'd only by the fortuitous Motion of little Particles; as if Stones by a chance Leap, fhould range themselves into an orderly and beautiful Palace; that Brutes are utterly deftitute of all Senfation; that the Tokens which they fometimes difcover of Joy, of Friendship, of Averfion, of Sadnefs, together with all the Impreffions of Pleasure, or Pain, are but the Refult of certain Springs that play in the Machine, according as the Matter is difpos'd; that Heat is not in the Fire, nor Hardnefs in the Marble, nor Moisture in the Water; but that all this is in the Soul, which by Thought and Reflection finds the Fire to be hot, the Marble hard, and the Water moift; and by no means in any fuch Qualities, which are meerly fictitious. In fhort, Defcartes, who infifts upon it as a Preliminary, that we fhould entertain a general Doubt of all Things, that we should fhut up all our Lights, fhould diveft our felves of all our pre-conceived Opinions, of

Custom,

Custom, of Education, of Senfe and Judgment, and all other Impreffions whatfoever, and all this only that we may arrive at fome little and fcanty Notice of Things, makes his Promifes vaftly difproportionable to his Demands. And when in order to the explaining the Nature of Things, he fays they are caus'd by a certain Figure, a certain Motion, and a certain Extenfion, he has faid all that he can; for he never goes into the Depth of a Subject; and tho' he profeffes himself a Follower of Democritus, yet he is unacquainted with the true Doctrine of that Philofopher. His Hypothefis of the LoadStone, with those little hooked Bodies, is arbitrary and groundlefs. His Account of the Ebbing and Flowing of the Sea, by the Impreffion of the Moon's Atmosphere, is found to be falfe; those Parts of the Water that are fubje& to the lunar Body being indeed rais'd, and not, as he conceives, deprefs'd. His Explication of the Motion of the Soul in the feveral Paffions, by the Conjunction of the Nerves and Fibres, terminating in the Glandula pinealis, is pure Chimera, there being really no Nerves that terminate in that Gland. On the Nature of Sounds, he advanced nothing that looks like a rational Conjecture. In a Word, he may not be unfitly re fembled to thofe Pythagoreans mention'd by Ariftotle, who were lefs folicitous to render the true Reafon of Things, than to reduce all to their own Principles and System. Yet as he aim'd rather at the Oftentation of Wit, than the Difcovery of the Truth, his Phyficks may afford fome Sort of Satisfaction to thofe who are moderate enough to take up with Probabilities. However, we can by no means defend the Haughtiness of fome of his Difciples, who treat all other Philofophers as meer Ideots, because

caufe they themselves have had the Fortune to make fome Noife, by reprefenting Philofophy under a new Drefs; as Novelties are always agreeable and furprizing.

XI.

The Chymifts, with their three Principles of Salt, Sulphur, and Mercury, have advanced nothing folid in the Doctrine of Nature; they are a Sort of feparate Traders in Philofophy, who not being able to embrace it in its full Extent and Compafs, have chofe a bounded Subject to exercife their limited Genius. We may reduce them to three Tribes or Orders; the firft, of those who profecute the Study of Nature in general; the fecond, of those who prepare Medicines; the third, of those who labour in the Tranfmutation of Metals, by giving them new Figures, new Colours, or new Confiftences. Thofe of the first and fecond Clafs may be allow'd to be rational Enquirers; fuch as were Albertus Magnus, Vanhelmont, and the Distillers. Thofe of the third are extravagant Pretenders, fuch as would ufurp upon the Rights of the Creator, in attempting to pro=duce new Creatures. As for the Cabalifts, and the Judicial Aftrologers, nothing can be more abfurd, than what they give us, for the Doctrine of Phyficks; and therefore I fhall not trouble my felf, or the Reader with it; nor with that of Cardan, entirely contain'd in his Book de Subtilitate. This I cannot excufe my felf from faying, that the Royal Society for the Improvement of natural Knowledge in England, the Academy of Philofophers establish'd fome Time fince by the King's Order at Paris, the great Induftry ufed by the late Cardinal de Medicis, to excite the Learned by his Encouragement and Example, together with the new History of Experiments,