90 DISCOURSE ON THE STUDY 



motion of material bodies and its cause, such as, 

 What will happen when a moving body is sur- 

 rounded on all sides by others not in motion ? What 

 will happen when a body not in motion is advanced 

 upon by a moving one? It is evident that the 

 answers to such questions as these can be no 

 other than laws of motion, in the sense we have 

 above attributed to laws of nature, viz. a statement 

 in words of what will happen in such and such 

 proposed general contingencies. Lastly, we are 

 led, by pursuing the analysis, and considering the 

 phenomenon of the aggregation of the parts of 

 material bodies, and the way in which they in- 

 fluence each other, to two other general pheno- 

 mena, viz., the cohesion and elasticity of matter; 

 and these we have no means of analysing further, 

 and must, therefore, regard them (till we see 

 reasons to the contrary) as ultimate phenomena t 

 and referable to the direct action of causes, viz. 

 an attractive and a repulsive force. 



(81.) Of force, as counterbalanced by opposing 

 force, we have, as already said, an internal con- 

 sciousness ; and though it may seem strange to us 

 that matter should be capable of exerting on mat- 

 ter the same kind of effort, which, judging alone 

 from this consciousness, we might be led to re- 

 gard as a mental one ; yet we cannot refuse the 

 direct evidence of our senses, which shows us 

 that when we keep a spring stretched with one 

 hand, we feel our effort opposed exactly in the same 

 way as if we had ourselves opposed it with the 

 other hand, or as it would be by that of another 

 person. The enquiry, therefore, into the aggre- 



