FALLACIES OF CONFUSION. 461 



The words Nature and Essence are grand instru- 

 ments of this mode of begging the question. As in 

 the well-known argument of the scholastic theolo- 

 gians, that the mind thinks always, because the essence 

 of the mind is to think. Locke had to point out, that 

 if by essence is here meant some property which must 

 manifest itself by actual exercise at all times, the pre- 

 miss is a direct assumption of the conclusion ; while if 

 it only means that to think is the distinctive property 

 of a mind, there is no connexion between the premiss 

 and the conclusion, since it is not necessary that a 

 distinctive property should be perpetually in action. 



The following is one of the modes in which these 

 abstract terms, Nature and Essence, are used as instru- 

 ments of this fallacy. Some particular properties of 

 a thing are selected, more or less arbitrarily, to be 

 termed its nature or essence ; and when this has been 

 done, these properties are supposed to be invested 

 with a kind of indefeasibleness ; to have become para- 

 mount to all the other properties of the thing, and 

 incapable of being prevailed over or counteracted by 

 them. As when Aristotle, in a passage which we 

 have already cited from Mr. Whewell, " decides that 

 there is no void on such arguments as this : in a void 

 there could be no difference of up and down ; for as 

 in nothing there are no differences, so there are none 

 in a privation or negation ; but a void is merely a pri- 

 vation or negation of matter; therefore, in a void, 

 bodies could not move up and down, which it is in 

 their nature to do*." In other words; It is the 

 nature of bodies to move up and down, ergo any phy- 

 sical fact which supposes them not so to move, cannot 

 be authentic. This mode of reasoning, by which a 



WHEWELL'S History of the Inductive Sciences, i., 44. 



