48 GENERAL VIEW AND BASIS OF SCIENTIFIC RESEARCH. 



possess very different* degrees of abstruseness, which 

 deepens as we pass from the conception of a single visible 

 thing, to those of its more hidden and invisible properties, 

 and onwards to those of its most recondite attributes and 

 relations. As, moreover, we mentally proceed from the 

 notion of such an object to that of a judgment, comparison, 

 and inference respecting it, the ideas we necessarily con- 

 ceive are each more complex and recondite. Nearly all 

 our mental activity may also be viewed as consisting of 

 conceptions of ideas more or less abstruse. Thus we con- 

 ceive the less abstruse ideas of colour, sound, solidity, 

 simple forms, &c. ; or the more recondite ones of each of 

 the various physical forces, the human mind, the great 

 principles of nature, various modes of motion, the universal 

 ether, &c. In proportion as ideas fail to produce a high 

 degree of mental change, so are they abstruse and dim cult 

 to realise completely ; abstruse ideas are therefore most 

 inadequate. 



Whilst the human mind appears incapable of intelli- 

 gently comprehending the creation of matter or force, it 

 can better understand the development of forms of matter. 

 Amongst the most abstruse ideas which we are able to 

 realise, are those of time and space, and the former is the 

 more abstract conception. The idea of number is that of 

 perceived repetition. The most abstract and essential 

 idea we can realise of matter and force is that of resist- 

 ance. The persistence of force is an ultimate truth, and 

 is the persistence of the Infinite Cause of all things. 

 Axiomatic ideas, such as that of ' contradictions cannot 

 co-exist,' are abstract ones ; they are those to which all 

 men at once assent as soon as they perceive their meaning ; 

 they are some of the latest, during life, of the ideas we 

 acquire, and are therefore not ' intuitive,' as they are 

 sometimes called. 



