SCIENCE 375 



as we before saw* to be the case with respect to our 

 idea of " number." 



This axiom about equality, though it can be illustrated 

 by any number of instances, can never be proved by 

 reasoning. It is a self-evident truth which reposes on 

 its own evidence as do the other axioms which are 

 characterised as " evident " in the second chapter of this 

 work. 



Self-evidence, then, is our ultimate ground for assent- 

 ing to such axioms, as well as to necessary principles and 

 to the fact of our own existence. 



We have already pointed out f how universal is the 

 desire of mankind to know the causes of circumstances 

 and events. To know this is, as before said, the aim 

 and object of the highest form of science. Particular 

 sciences may be devoted to ascertaining that certain 

 things are, and the circumstances of their being their 

 successions and co-existences but no such knowledge of 

 mere phenomena will suffice to constitute science itself. 

 Such science is but another term for philosophy the 

 science of sciences which is what we are concerned with 

 in this chapter. 



If we examine our minds as to what our idea of 

 " cause " is when that conception is called forth, we shall L^ 

 see that it stands in close relation to our perception and 

 idea of " change." 



When some change occurs, or when anything strikes 

 us as being a new thing, we spontaneously look out for 

 its cause. The truth concerning causation, which our 

 mind recognises as being necessary and self-evident, is 

 the principle that " every new existence is due to some 

 cause" and this is quite in harmony with that spon- 



* See ante, p. 264. t See ante, p. 268. 



