ON THE PSYCHO-PHYSICAL VIEW OF NATURE. 541 



Emotions in Man and Animals ' a year after. These 

 writings did more than any others to impress upon 

 philosophers the genetic or historical view, the existence 

 of an unbroken chain or transition from the lower to the 

 higher and the highest forms of animal structures, and 

 culminated in the well-known expression of Darwin, that 

 "in a series of forms graduating insensibly from some 

 ape-like creature to man as he now exists, it would be 

 impossible to fix at any definite point when the term 

 ' man ' ought to be used." ] This dictum has been the 

 theme on which endless variations have been played 

 down to the present day Prof. Ernest Haeckel's address 

 to the Congress of Zoology at Cambridge in 1898 being 

 the latest summary of the physical aspect of the problem. 

 But the problem has also a psycho-physical side, and this 

 aspect is concentrated in the problem of language. Even 

 those philologists who, like August Schleicher and Max 

 Miiller, look upon the science of language as a natural 

 science, bring in at this point the accumulated and 

 weighty evidence of the historical, psychological, and 

 philosophical researches into the growth and development 

 of human speech and human thought, as absolutely 

 negativing the possibility of a gradual transition from the 4s. 



The dividing 



brute to the human creation. To the latter, language, ime between 



man and 



which he considers to be the union of definite concepts brute - 

 with definite names, is the Eubicon which cannot be 

 crossed, 2 the chasm which divides that portion of the 



1 'Descent of Man,' 1st ed., vol. 

 i. p. 235. 



See Max Miiller, 'The Science 

 of Thought,' patsim, notably chap, 

 iv. p. 177, where he quotes and 

 maintains his dictum of 1861 ('Lec- 



tures on the Science of Language,' 

 vol. i. p. 403) : " Language is our 

 Rubicon, and no brute will dare to 

 cross it." Referring to Schleicher, 

 he says (p. 164) : " Professor 

 Schleicher, though an enthusiastic 



