64 EVOLUTION AND MAN S PLACE IN NATURE 



of the hair, in facial expression, in measurements of 

 the skull, in evolutions of the brain, numerous as these 

 prove to be, are not such as to warrant classification 

 of new species. Transfer observation to the rational 

 life. Variations are here incalculably more numerous, 

 and yet in the midst of them the identity of the 

 rational power is manifest. Animal variations may 

 lead to origin of species. Mental differences, even 

 greater in range, do not break the unity of the 

 race. We are now contemplating a single order of 

 life spread all the world over, the laws of whose 

 development are different from those applicable to 

 lower orders of life. 



All the characteristics of this higher life unfold 

 from the rational exercise which concerns itself at 

 once with interpretation of sensory experience, and 

 regulation of personal conduct. (^ Every thing belonging 

 to the reflective exercise, to acquisition of skill, to 

 division of labour, to cultivation of art, to exercise of 

 literary gift, and to formation of moral character, un 

 folds from the simplest stage of rational exercise&quot;?) 

 The line is clear, and it is a single line, from such a 

 starting-point as this, leading all men onwards to the 

 ultimate problem of metaphysic, the problem of the 

 Universe itself. For the humblest thinkers, and for 

 the greatest thinkers which science and philosophy 

 claim, the conditions of thinking are the same. 

 Accordingly, it holds true, to a degree quite mar 

 vellous in view of the great diversity in gifts and 

 attainments, that the problems raised are identical. 

 These facts present the evidence that rational life is 

 essentially one, with no such grounds of severance as 

 mark off diverse species of organic life. 



