NOVUM ORGANUM. 47 



properties, the second that of occult properties 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 labour in the consideration of the secondary quali 

 ties of things and the operations of attraction, repulsion, 

 attenuation, inspissation, dilatation, astringency, separa 

 tion, maturation, 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 com 

 position, or at any rate neglect to advance by greater and 

 more diligent observation to the third and fourth qualities, 

 thus terminating their contemplation 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 investi 

 gation 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, cor 

 ruption, augmentation, diminution, alteration, and transla 

 tion. For this is their meaning : if a body, unchanged in 

 other respects, is moved from its place, this is translation ; 

 if the place 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 sug 

 gest 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 violent motion, 



