NOVUM ORGANUM 329 



animals, plants, minerals, and is thence easily led to imagine 

 that there exist in nature certain primary forms which she 

 strives to produce, and that all variation from them arises from 

 some impediment or error which she is exposed to in com- 

 pleting her work, or from the collision or metamorphosis of 

 different species. The first hypothesis has produced the doc- 

 trine of elementary properties, the second that of occult proper- 

 ties and specific powers; and both lead to trifling courses of 

 reflection, in which the mind acquiesces, and is thus diverted 

 from more important subjects. But physicians exercise a 

 much more useful labor in the consideration of the secondary 

 qualities of things, and the operations of attraction, repulsion, 

 attenuation, inspissation, dilation, astringency, separation, ma- 

 turation, and the like ; and would do still more if they would 

 not corrupt these proper observations by the two systems I 

 have alluded to, of elementary qualities and specific powers, by 

 which they either reduce the secondary to first qualities, and 

 their subtile and immeasurable composition, or at any rate 

 neglect to advance by greater and more diligent observation 

 to the third and fourth qualities, thus terminating their con- 

 templation prematurely. Nor are these powers (or the like) 

 to be investigated only among the medicines for the human 

 body, but also in all changes of other natural bodies. 



A greater evil arises from the contemplation and investiga- 

 tion rather of the stationary principles of things from which, 

 than of the active by which things themselves are created. For 

 the former only serve for discussion, the latter for practice. 

 Nor is any value to be set on those common differences of 

 motion which are observed in the received system of natural 

 philosophy, as generation, corruption, augmentation, diminu- 

 tion, alteration, and translation. For this is their meaning: if 

 a body, unchanged in other respects, is moved from its place, 

 this is translation ; if the places and species be given, but the 

 quantity changed, it is alteration ; but, if from such a change, 

 the mass and quantity of the body do not continue the same, 

 this is the motion of augmentation and diminution ; if the 

 change be continued so as to vary the species and substance, 

 and transfuse them to others, this is generation and corruption. 

 All this is merely popular, and by no means penetrates into 

 nature ; and these are but the measures and bounds of motion, 

 and not different species of it ; they merely suggest how far, and 

 not how or whence. For they exhibit neither the affections of 

 bodies nor the process of their parts, but merely establish a 

 division of that motion, which coarsely exhibits to the senses 

 matter in its varied form. Even when they wish to point out 

 something relative to the causes of motion, and to establish a 

 division of them, they most absurdly introduce natural and vio- 



