ejsentialto Matter, &c. 23

matter, are not powers implanted in mat-ter, or possible to be made inherent in it;but (therefore) impulse, or force impressedupon it ab extra. We are apt to think thatit is a certain natural quality, or power, im-planted in the matter of a stone, v. g. andinherent in it, that makes it tend to theearth sg) : but, by what is said in the last

paragraph,

(g) Even so great a man as Borelli seems to have beenof this epinion. In the chapter de caufis fs’ principiismotus (the ad of his book de vi percuffionis) he fays, Tan-dem summd contentione controvertitur , an all qua corporamoveri possunt aseipsis, velpotius quicquid movetur, a di-JiinSio separate que motor e propelli dibeat: & prose Sib, uta pojiremo exordiamur , evidentijsimum ejl aliqua corpora adisiinSlo, fff cxtir.no motore impelli, sic ea omnia qua ve-huntur, pcrcutiunlur , aut projiciuntur , manifestiff me ab.externo impulsore promoventur j fed an reliqua omnia , quatn mundo moventur , pariter ab extrinseco principio , iff can-s& prcpellantur , hoc prose Sib imposstbile & incredibile vide -/ar, quandoquidem corpora gravia , ta animalia per fe vi-dentur moveri , scilicet d causa fs* principio intrinseco , £sV."What difference there is to be asijgned between the mov-ing principle in an animal, and in a heavy body descend-ing, we shall see below ; only I think it was not rightto conclude them under one head. The expression [sub-siantia animajlica,~\ which farther on he fays is both a-gent and patient , without a clear idea of it i n the mind oftils person that writes, and an explication of that idea, toC 4 communicate