PLEASURES OF SCIENCE 15 



mental properties of matter without observing what goes on around 

 us, and trying experiments upon the nature and motion of bodies. 

 Thus, the man whom we have supposed shut up could not possibly find 

 out beyond one or two of the very first properties of matter, and those 

 only in a very few cases ; so that he could not tell if these were 

 general properties of all matter or not. He could tell that the objects 

 he touched in the dark were hard and resisted his touch ; that they were 

 extended and were solid ; that is, that they had three dimensions, 

 length, breadth, and thickness. He might guess that other things 

 existed beside those he felt, and that those other things resembled what 

 he felt in these properties, but he could know nothing for certain, and 

 could not even conjecture much beyond this very limited number of 

 qualities. He must remain utterly ignorant of what really exists in 

 nature, and of what properties matter in general has. These properties, 

 therefore, we learn by experience ; they are such as we know bodies to 

 have ; they happen to have them they are so formed by Divine Pro- 

 vidence as to have them but they might have been otherwise formed ; 

 the great Author of Nature might have thought fit to make all bodies 

 different in every respect. We see that a stone dropped from our hand 

 falls to the ground ; this is a fact which we can only know by expe- 

 rience ; before observing it, we could not have guessed it, and it is 

 quite conceivable that it should be otherwise : for instance, that when 

 we remove our hand from the body it should stand still in the air ; or 

 fly upward, or go forward, or backward, or sideways ; there is nothing 

 at all absurd, contradictory, or inconceivable in any of these supposi- 

 tions ; there is nothing impossible in any of them, as there would be 

 in supposing the stone equal to half of itself, or double of itself; or 

 both falling down and rising upwards at once ; or going to the right 

 and the left at one and the same time. Our only reason for not at once 

 thinking it quite conceivable that the stone should stand in the air, or 

 fly upwards, is, that we have never seen it do so, and have become 

 accustomed to see it do otherwise. But for that, we should at once 

 think it as natural that the stone should fly upwards or stand still, as 

 that it should fall. But no degree of reflection for any length of time 

 could accustom us to think 2 and 2 equal to any thing but 4, or the 

 whole to be equal to a part. 



After we have once by observation or experiment ascertained certain 

 things to exist in fact, we may then reason upon them by means of 

 mathematics ; that is, we may apply mathematics to our experimental 

 philosophy, and then such reasoning becomes absolutely certain, taking 

 the fundamental facts for granted. Thus, if we find that a stone falls 

 in one direction when dropped, and we further observe the peculiar 

 way in which it falls, that is, quicker and quicker every instant till it 

 reaches the ground, we learn the rule or the proportion by which the 

 quickness goes on increasing ; and we further find, that if the same 

 stone is pushed forward on a table, it moves in the direction of the 

 push, till it is either stopped by something, or comes to a pause, by 

 rubbing against the table, and being hindered by the air. These are all 

 facts which we learn by observing and trying, and they might all have 

 been different if matter and motion had been otherwise constituted ; 

 but supposing them to be as they are, and as we find them, we can, by 



