74 Sir ISAAC NEWTO N’s Book. I.

find in the visible world. Other philosophers have complainedthat they were able to account for too little of nature : DesCartes finds that his principles were more than sufficient to ac-count for all her phænomena, and seems only to fear lest he shouldaccount for too much. Therefore he has recourse to the phe-nomena, not because he would prove any thing from them ;for he takes care that we should not have so mean an opinionof his philosophy, as to imagine he would establish it on facts;but that he might be able to determine his mind to considersome of those innumerable effects, which he judged might pro-ceed from the same causes, rather than others. He likewiseacknowledges *, that the same effect might be deduced, fromhis principles, many different ways ; and that nothing per-plexed him more than to know which of them obtained innature. In those passages he magnifies his principles, in orderto conceal the weakness of his system, with an affectation thatonly serves to make it more evident, and appears unworthy ofso great a man.

3. Des Cartes , by placing the essence of matter in ex-tension alone, gave occasion to others to draw consequences,from this doctrine, of a dangerous nature ; which undoubtedlyhe would have disowned, tho 1 ’tis not eafy to fee how he couldhave got rid of them. As we are not able to conceive thatspace can be annihilated, or that there ever was a time whenspace or expansion was not; so if we allow that extension aloneconstitutes the essence of matter, we cannot but ascribe in-finity, eternity, and necessary existence to it. In this mannerSpinoza reasons from the Cartesian principles, affirming that

* Sed confiteri me etiam oportet potentiam naturae esse adeo amplam, ut nullumtrre amplius particularem effectum obscrvem, quern statim variis modis ex iis prin-cipiis deduct posse non agnoscam : nihilque ordinario mihi difficilius videri, quaminvenire quo ex his modis inde dependet. De Methodo, § 6.

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matter