430 



OPERATIONS SUBSIDIARY TO INDUCTION. 



and not agreements at all, or, if 

 real agreements, were comparatively 

 trifling, and had no connection with 

 the phenomenon the law of which was 

 sought. 



Aristotle, philosophising on the 

 subject of motion, remarked that cer- 

 tain motions apparently take place 

 spontaneously ; bodies fall to the 

 ground, flame ascends, bubbles of air 

 lise in water, &c. : and these he called 

 natural motions ; while others not 

 only never take place without inter- 

 nal incitement, but even when such 

 incitement is applied tend spontane- 

 ously to cease ; which, to distinguish 

 them from the former, he called vio- 

 lent motions. Now, in comparing 

 the so-called natural motions with 

 one another, it appeared to Aristotle 

 that they agreed in one circumstance, 

 namely, that the body which moved 

 (or seemed to move) spontaneously 

 was moving towards its ovm place; 

 meaning thereby the place from 

 whence it originally came, or the 

 place where a great quantity of matter 

 similar to itself was assembled. In 

 the other class of motions, as when 

 bodies are thrown up in the air, they 

 are, on the contrary, moving froin 

 their ovm place. Now, this concep- 

 tion of a body moving towards its 

 own place may justly be considered 

 inappropriate ; because, though it ex- 

 presses a circumstance really found 

 in some of the most familiar instances 

 of motion apparently spontaneous, yet, 

 first, there are many other cases of 

 such motion, in which that circum- 

 stance is absent : the motion, for 

 instance, of the earth and planets. 

 Secondly, even when it is present, the 

 motion, on closer examination, would 

 often be seen not to be spontaneous : 

 as, when air rises in water, it does 

 not rise by its own nature, but is 

 pushed up by the superior weight of 

 the water which presses upon it. 

 Finally, there are many cases in 

 which the spontaneous motion takes 

 place in the contrary direction to 

 what the theory considei-s as the 

 body's own place ; for iustanc*, when 



a fog rises from a lake, or when water 

 dries up. The agreement, therefore, 

 which Aristotle selected as his prin- 

 ciple of classification did not extend 

 to all cases of the phenomenon he 

 wanted to study, spontaneous motion ; 

 while it did include cases of the ab- 

 sence of the phenomenon, cases of 

 motion not spontaneous. The con- 

 ception was hence "inappropriate." 

 We may add that, in the case in 

 question, no conception would be 

 appropriate ; there is no agreement 

 which runs through all the cases of 

 spontaneous or apparently sponta- 

 neous motion and no others : they 

 cannot be brought under one law : it 

 is a case of Plurality of Causes.* 



§ 5. So much for the first of Dr. 

 Whewell'a conditiona, that concep 

 tions most be appropriate. The bo- 

 cond is, that they shall be "clear ;" 

 and let ns consider what this implies. 

 Unless the conception corresponds to 

 a real agreement, it has a worse defect 



* Other examples of inappropriate Con- 

 ceptions are given by Dr. Whcwell (Phil. 

 Ind. Sc, ii. 185) as follows :—" Aristotlo 

 and his followers endeavoured in vain to 

 account for the mechanical relation of 

 forces in the lever, by applying the inap- 

 propriate geometrical conceptions of tho 

 properties of the circle : they failed in 

 explaining the form of the luminous spot 

 made by the sun shining through a hole, 

 because they appUed the inappropriate 

 conception of a circular quality in the 

 sun's light ; they speculated to no purpose 

 about the elementary composition of bodies, 

 because they assumed the inappropriate 

 conception of likeness between the elements 

 and the compound, instead of the genuine 

 notion of elements merely determining th» 

 qualities of the compound." But in these 

 cases there is more than an inappropriate 

 conception ; there is a false conception ; 

 one which has no prototype in nature, 

 nothing corresponding to it in facrs. This 

 is evident in the last two examples, and ia 

 equally true in the first; the "properties 

 of the circle, " which were referred to, being 

 purely fantastical. There is, therefore, aa 

 error beyond the wrong choice of a prin- 

 ciple of generalisjition ; there is a false 

 assumption of matters of fact The attempt 

 is made to resolve certain laws of nature 

 into a more general law, that law not being 

 one which, though real, la inuppropriate, 

 but oa« wholly ima^arj^. 



