Chap. II. ANTIENT ISI ET A PH Y S I CS. 17 



have derived not only our feiifatlons, but our ideas, from his ethers 

 and fluids ; and then his fyftem of materiahfm would have been as 

 complete as that of a Frenchman, the Abbe Prade, who de- 

 rives the whole operations of our mind from matter and motion, in 

 a work which he has entitled, V Homme Machine. But though Sir 

 Ifaac has not faid, in ib many words, that our ideas, as well as our 

 fenfations, arc derived from ethers and fluids, he has in efFe£t main- 

 tained that dodtrine : For if it be true, that thefe ethers and fluids 

 produce our fenfations, it follows of neccfiary confequence, that 

 they produce our ideas, which all originate from our fenfations; 

 the firft ideas we form being of objeds of fenfe*, the perceptions of 

 which are what we call fenfations. And as ideas are the founda- 

 tion of arts and fciences, and of our whole knowledge in this life, 

 it follows, of neceflary confequence, that thefe ethers and fluids pro- 

 duce all our knowledge, and all the operations of the mind necef- 

 fary for attaining knowledge ; which makes the fyftem of materia- 

 lifm perfedly compleat. 



As to the motion of our own bodies by our own minds, I think 

 we have the clearefl: proof of it that we can have of any thing; and 

 that is confcioufnefs, by which we know that our bodies are moved 

 by our minds, and in a very wonderful manner, not immediately 

 and diredly, but by the intervention of our animal mind ; for our 

 intelledual mind does not operate immediately and diredly upon our 

 bodies, but only wills that the animal mind fhould move them; and, 

 accordingly, that mind does fo by the means of mufcles, fmews, and 

 bones: So that by a fmgle ad of the will, this complicated machine, 

 as I have elfewhere obferved f, is fet a going, and made to move our 

 bodies. Now, I cannot believe that confcioufnefs, the fureft evi- 

 dence we have of any thing, mifguides me in this cafe, Liit I muft 

 hold that my body is truly moved by my mind. 



Vol. VI. C Having 



* See Vol. V. of this work, p. 168. f Ibid. p. 108. 



