MODERN CONCEPTION OF MATTER 37 



nature of things becomes capable of being appre- 

 hended, perceptible, visible. In this sense, then, 

 matter is simply the visibility of the will, or the 

 bond between the world as will and the world as 

 idea." " The essence of matter is acting ; it is act- 

 ing itself in the abstract ; thus acting in general 

 apart from all difference of the kind of action ; it is 

 through and through causality. On this account 

 it is itself, as regards its existence, not subject to 

 the law of causality, and thus has neither come 

 into being nor passes away, for otherwise the law of 

 causality would be applied to itself. Since, now, 

 causality is known to us a priori^ the conception of 

 matter as the indestructible basis of all that exists 

 can so far take its place in the knowledge we 

 possess a priori^ inasmuch as it is only the realisa- 

 tion of an a priori form of our knowledge. For 

 as soon as we see anything that acts or is causally 

 efficient, it presents itself eo ipso as material ; and 

 conversely, anything material presents itself as 

 necessarily active or causally efficient. They are, in 

 fact, interchangeable conceptions. Therefore the 

 word actual is used as synonymous with material." 



We quote Schopenhauer at such length because, 

 as we shall see later, he reached a metaphysical 

 conception of matter which is being daily cor- 

 roborated by scientific discovery. 



Towards the end of the nineteenth century the 



