376 ELEMENTS OF SCIENCE 



taneous habit of mankind before mentioned. It is also 

 a truth, the self-evidence of which a little reflection will 

 make clear. Thus, a thing which is new cannot have 

 caused itself, because it could never have acted before it 

 came into existence. It must, therefore, have been 

 brought into being by something else. But every change 

 which takes place in a thing already existing is also, to 

 a certain extent, a new existence, for it is a new state or 

 mode of existence. It must, therefore, either be due to 

 some antecedent mode of existence or to something dis- 

 tinct from it. Thus, if a door which was open is now 

 no longer open, it must have been acted on by something 

 else a current of air, or what not. If a cat is now 

 awake which was asleep, this must be due either to 

 something external which has awakened it, or to some 

 vital action of its own frame, which has aroused it from 

 its dormant condition. 



Again, all and every object made known to us by our 

 senses is seen to be necessarily the product of some 

 cause or causes external to itself. This is, of course, 

 most manifestly the case with every product of human 

 art ; but every stone which we tread upon, or every patch 

 of sand or mud, must have come to be as it is through 

 the action of antecedent causes and conditions which 

 have made it to be as it is and not otherwise. Not only 

 the more or less complex structure of any solid body, 

 but its size, position, divisibility and its existence at the 

 time and manner in which it does exist, are all due to 

 antecedent actions of other things which have determined 

 its present conditions of existence. Even a portion of 

 matter, which, so far as we know, is not made up of other 

 material substances such, e.g., as a diamond or a piece of 

 gold demands a cause for its relation to things around it 

 and for its own size and internal conditions. The two 



