CHAPTER XX 



THE THYSICAL EVOLUTION OF MAN 



Emerson in his essay on Plato says (p. 21): "If the tongue 

 had not been framed for articulation, man would still be a 

 beast in the forest." Like many of Emerson's sayings the 

 passage is striking, but we hope to show in this chapter that it is 

 only very partially true. Nay more, we trust to demonstrate 

 by the close of the chapter that change in two words of the above 

 quotation would make it a correct and telling statement. 



Much also has been said and written on the "noble upright 

 posture" of man, and "the human face divine," not a little of 

 which is as ludicrous as by strict standards of the older theology 

 it should have been denounced as impious. Darwin's words 

 in this connection are ever true: "It is our natural prejudice, 

 and that arrogance which made our forefathers declare that 

 they were descended from demigods," that causes us to foster 

 many a priori or baseless convictions regarding man. 



Lamarck, Spencer, Darwin, Hseckel, and many succeeding 

 have minutely compared man's physical frame with that of the 

 higher mammals below him. Their conclusions, that there is 

 a direct continuity in structural detail, which even impresses 

 itself on the mental and moral acts, have been so fully verified 

 that few now reject their conclusions, and a recapitulation of 

 their results here would be superfluous. 



But all are agreed that the outstanding characteristics of 

 man are his elaborate and complex brain structure, and his 

 inmiensely superior mental powers in connection therewith. 

 In the present chapter we desire to ascertain whether, on the 

 l)rinciple of cause and efl'ect, of action and reaction, of environal 

 stimulus and proenvironal response, a definite explanation can 

 be given for the origin and increasing development of this 

 superiority, of the causes which have effected such, and whether 

 stages in the process cannot at present be traced. 



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