HI THE ORIGIN OF THE IMPRESSIONS 91 



body. Place it in any figure, nothing ever results but 

 figure, or the relation of parts. Move it in any manner, 

 you still find motion or a change of relation. 'Tis ab- 

 surd to imagine that motion in a circle, for instance, 

 should be nothing but merely motion in a circle ; while 

 motion in another direction, as in an ellipse, should also be 

 a passion or moral reflection; that the shocking of two 

 globular particles should become a sensation of pain, and 

 that the meeting of the triangular ones should afford a 

 pleasure. Now as these different shocks and variations 

 and mixtures are the only changes of which matter is sus- 

 ceptible, and as these never afford us any idea of thought 

 or perception, 'tis concluded to be impossible, that thought 

 can ever be caused by matter. 



" Few have been able to withstand the seeming evidence 

 of this argument ; and yet nothing in the world is more 

 easy than to refute it. We need only reflect upon what has 

 been proved at large, that we are never sensible of any con- 

 nection between causes and effects, and that 'tis only by 

 our experience of their constant conjunction we can 

 arrive at any knowledge of this relation. Now, as all ob- 

 jects which are not contrary are susceptible of a constant 

 conjunction, and as no real objects are contrary, 1 have in- 

 ferred from these principles (Part III. 15) that, to consider 

 the matter a priori, anything may produce anything, and 

 that we Shall never discover a reason why any object may 

 or may not be the cause of any other, however great, or 

 however little, the resemblance may be betwixt them. This 

 evidently destroys the precedent reasoning, concerning the 

 cause of thought or perception. For though there appear 

 no manner of connection betwixt motion and thought, the 

 case is the same with all other causes and effects. Place 

 one body of a pound weight on one end of a lever, and an- 

 other body of the same weight on the other end ; you will 

 never find in these bodies any principle of motion depend- 

 ent on their distance from the centre, more than of thought 



