MECHANICAL LAWS. 211 



of matter which are mainly concerned in the 

 production of cosmical phenomena ? 



It will readily be perceived that the discussion 

 of this point must necessarily require some effort 

 of abstract thought. The laws and properties of 

 which we have here to speak the laws of motion 

 and the universal properties of matter are so 

 closely interwoven with our conceptions of the 

 external world, that we have great difficulty in 

 conceiving them not to exist, or to exist other 

 than they are. When we press or lift a stone, we 

 can hardly imagine that it could, by possibility, 

 do otherwise than resist our effort by its hard- 

 ness and by its heaviness, qualities so familiar to 

 us : when we throw it, it seems inevitable that 

 its motion should depend on the impulse we give, 

 just as we find that it invariably does. 



Nor is it easy to say how far it is really pos- 

 sible to suppose the fundamental attributes of 

 matter to be different from what they are. If 

 we, in our thoughts, attempt to divest matter of 

 its powers of resisting and moving, it ceases to 

 be matter, according to our conceptions, and we 

 can no longer reason upon it with any distinct- 

 ness. And yet it is certain that we can conceive 

 the laws of hardness and weight and motion to 

 be quite different from what they are, and can 

 point out some of the consequences which would 

 result from such difference. The properties of 

 matter, even the most fundamental and universal 



