404 NOVUM ORGANUIL [BOOK i. 



introduce natural and violent motion, which is also a popular 

 notion, since every violent motion is also in fact natural, that is 

 to say, the external efficient puts nature in action in a different 

 manner to that which she had previously employed. 



But if, neglecting these, any one were for instance to observe 

 that there is in bodies a tendency of adhesion, so as not to suffer 

 the unity of nature to be completely separated or broken, and a 

 vacuum* to be formed, or that they have a tendency to return 

 to their natural dimensions or tension, so that, if compressed or 

 extended within or beyond it, they immediately strive to recover 

 themselves, and resume their former volume and extent ; or that 

 they have a tendency to congregate into masses with similar 

 bodies, the dense, for instance, towards the circumference of 

 the earth, the thin and rare towards that of the heavens. These 

 and the like are true physical genera of motions, but the others 

 are clearly logical and scholastic, as appears plainly from a com 

 parison of the two. 



Another considerable evil is, that men in their systems and 

 contemplations bestow their labour upon the investigation and 

 discussion of the principles of things and the extreme limits of 

 nature, although all utility and means of action consist in the 

 intermediate objects. Hence men cease not to abstract nature 

 till they arrive at potential and shapeless matter,* and still per 

 sist in their dissection, till they arrive at atoms ; and yet were 

 all this true, it would be of little use to advance man s estate. 



LXVII. The understanding must also be cautioned against 

 the intemperance of systems, so far as regards its giving or with 

 holding its assent ; for such intemperance appears to fix and 

 perpetuate idols, so as to leave no means of removing them. 



These excesses are of two kinds. The first is seen in those 

 who decide hastily, and render the sciences positive and dicta 

 torial. The other in those who have introduced scepticism, and 

 vague unbounded inquiry. The former subdues, the latter 

 enervates the understanding. The Aristotelian philosophy, after 



e Galileo had recently adopted the notion that nature abhorred a 

 vacuum for an axiomatic principle, and it was not till Torricelli, his dis 

 ciple, had given practical proof of the utility of Bacon s method, by the 

 discovery of the barometer (1643), that this error, as also that expressed 

 below, and believed by Bacon, concerning the homoeopathic tendencies ot 

 bodies, was destroyed. Ed. 



f Donee ad materiam potentialem et infonnem ventumfuerit. Nearly 

 all the ancient philosophers admitted the existence of a certain primitive 

 and shapeless matter as the substratum of things which the creative 

 power had reduced to fixed proportions, and resolved into specific sub 

 stances. The expression potential matter refers to that substance form 

 ing the basis of tlia Peripatetic system, which virtually contained all tlm 

 Vormd that it was in the power of the efficient cause to draw out of it. Ed, 



