252 L ikenesses ; r, Ph ilosoph ical A natomy 



otherwise than in our conception; and to seek their objective 

 sub-stratum, we must seek the concrete objects of which they 

 are the symbols.' 



Natural classification, indeed, though formed by the mind, 

 does not depend on the mind. It is not arbitrary, but is 

 governed by the external realities of things. It is not that 

 we choose to separate bats and whales from birds and fishes 

 respectively, and put them both in the same class as that 

 which contains also the lion and the antelope. We are com- 

 jpelled, by the multitudinous facts of animal structure, so 

 to separate and so to class them. Moreover, such zoological 

 classification is only possible because different animals are 

 found to have like parts (parts alike as to their relations of 

 position to other parts) which can be compared and con- 

 trasted, and can, by the agreements and differences they 

 present, furnish us with the determining and limiting char- 

 acters of the different natural groups. 



As it is with respect to the various groups of animals and 

 plants, so it is with respect to the parts and organs which 

 together compose each individual animal or plant. As the 

 human mind surveys these parts and organs in different 

 lights, it finds different series of unlikenesses and Hkenesses, 

 extending along that line of thought which it elects to follow. 

 Here again, however, the resulting groups of likenesses can- 

 not be freely and arbitrarily established, but must follow 

 objective reality. It is thus that fanciful notions which do not 

 respond to the realities of things, have to succumb and give 

 place to conceptions which do harmonise with such realities. 



Every bird and beast, every fish and insect, is formed of 

 a complex aggregation of parts which are grouped together 

 into an harmonious interdependency and have a multitude 

 of relations, amongst themselves, of different kinds. The 

 mind detects a certain number of these relations as it con- 

 templates the various component parts of any individual 



