CAUSATION 



in our first chapter, we can in nowise do. As 

 was there pointed out, neither by the artifice 

 of an intermolecular ether or of centres of at- 

 tractive and repulsive force, nor by any other 

 imaginable artifice, can we truly conceive one 

 particle of matter acting upon another. What 

 we do know is neither more nor less than what 

 is given in consciousness, namely, that certain 

 coexistences invariably precede or follow certain 

 other coexistences. That matter as objectively 

 existing may exert upon matter some constrain- 

 ing power which, as forever unknowable by us, 

 may be called an occulta visy I readily grant. 

 Thought is not the measure of things, and it 

 was therefore unphilosophical in Hume to deny 

 the existence of any such unknown power. 

 Things may exist, in heaven and on earth, 

 which are neither dreamt of in our philosophy 

 nor conceivable by our intelligence. Respecting 

 the external reality we say nothing : we only 

 afiirm that no such occulta vis is given in the 

 phenomenon of causation. Any hypothesis which 

 postulates such an unknown element as a means 

 of explaining the phenomenon is unverifiable, 

 and, as such, science cannot admit it, nor can 

 our Cosmic Philosophy admit it. 



Nevertheless the belief that causation implies 

 something more than mere invariability of se- 

 quence has been a persistent belief; and, as 

 such, it is a fact which philosophy is required 

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