ABSTRACTION. 203 



wanted to study, spontaneous motion ; while it did include 

 cases of the absence of the phenomenon, cases of motion not 

 spontaneous. The conception 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 spontaneous 

 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's conditions, 

 that conceptions must be appropriate. The second is, that 

 they shall be " clear :" and let us consider what this implies. 

 Unless the conception corresponds to a real agreement, it has 

 a worse defect than that of not being clear ; it is not appli- 

 cable to the case at all. Among the phenomena, therefore, 

 which we are attempting to connect by means of the concep- 

 tion, we must suppose that there really is an agreement, and 

 that the conception is a conception of that agreement. In 

 order, then, that it may be clear, the only requisite is, that 

 we shall know exactly in what the agreement consists ; that 

 it shall have been carefully observed, and accurately remem- 

 bered. We are said not to have a clear conception of the 

 resemblance among a set of objects, when we have only a gene- 



* Other examples of inappropriate conceptions are given by Dr. Whewell 

 (Phil. Ind. Sc. ii. 185) as follows : " Aristotle and his followers endeavoured 

 in vain to account for the mechanical relation of forces in the lever, by applying 

 the inappropriate geometrical conceptions of the properties of the circle : they 

 failed in explaining the form of the luminous spot made by the sun shining 

 through a hole, because they applied 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 the qualities of the compound." But in these 

 cases there is more than an inappropriate conception ; there is a false concep- 

 tion ; one which has no prototype in nature, nothing corresponding to it in 

 facts. This is evident in the last two examples, and is equally true in the first ; 

 the "properties of the circle" which were referred to, being purely fantastical. 

 There is, therefore, an error beyond the wrong choice of a principle of genera- 

 lization ; 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, is inappropriate, but one wholly imaginary. 



