CANTO in. PROGRESS OF THE MIND. 93 



Untipt with claws the circling fingers close, 



With rival points the bending thumbs oppose, 



Trace the nice lines of Form with sense refined, 



And clear ideas charm the thinking mind. 



Whence the fine organs of the touch impart 



Ideal figure, source of every art; 



Time, motion, number, sunshine or the storm, 



But mark varieties in Nature's form. 130 



Trace the nice lines of form,}. 125. When the idea of solidity is 

 excited a part of the extensive organ of touch is compressed by some 

 external body, and this part of the sensorium so compressed exactly 

 resembles in figure the figure of the body that compressed it. Hence 

 when we acquire the idea of solidity, we acquire at the same time 

 the idea of figure; and this idea of figure, or motion of a part of the 

 organ of touch, exactly resembles in its figure the figure of the body 

 that occasions it; and thus exactly acquaints us with this property of 

 the external world. 



Now, as the whole universe with all its parts possesses a certain 

 form or figure, if any part of it moves, that form or figure of the 

 whole is varied. Hence, as motion is no other than a perpetual vari- 

 ation of figure, our idea of motion is also a real resemblance of the 

 motion that produced it. 



Hence arises the certainty of the mathematical sciences, as they 

 explain these properties of bodies, which are exactly resembled by 

 our ideas of them, whilst we are obliged to collect almost all our 

 other knowledge from experiment; that is, by observing the effects 

 exerted by one body upon another. 



