VI CONCERNING NECESSARY TRUTHS 149 



doubtedly find in our minds the idea of something 

 resident in the cause which, as we say, produces 

 the effect, and we call this something Force, Power, 

 or Energy. Hume explains Force and Power as 

 the results of the association with inanimate causes 

 of the feelings of endeavour or resistance which we 

 experience, when our bodies give rise to, or resist, 

 motion. 



If I throw a ball, I have a sense of effort which 

 ends when the ball leaves my hand ; and, if I catch 

 a ball, I have a sense of resistance which comes 

 to an end with the quiescence of the ball. In the 

 former case, there is a strong suggestion of some- 

 thing having gone from myself into the ball ; m 

 the latter, of something having been received from 

 the ball. Let any one hold a piece of iron near a 

 strong magnet, and the feeling that the magnet 

 endeavours to pull the iron one way, in the same 

 manner as he endeavours to pull it in the opposite 

 direction, is very strong. 



As Hume says : 



" No animal can put external bodies in motion without the 

 sentiment of a nisus, or endeavour ; and eveiy animal has a 

 sentiment or feeling from the stroke or blow of an external 

 object that is in motion. These sensations, which are merely 

 animal, and from which we can, & priori, draw no inference, we 

 are apt to transfer to inanimate objects, and to suppose that they 

 have some such feelings whenever they transfer or receive 

 motion." (IV. p. 91, note.) 



It is obviously, however, an absurdity not less 



