EVOLUTION AND THE HIGHER HUMAN LIFE 279 



ance with the laws and processes of nature. But the 

 seeker after truth is fearless of consequences. He knows 

 that truth cannot contradict itself; and if those to 

 whom he looks for authority give him conflicting ac- 

 counts of nature's history, he knows that one of these 

 must be less surely grounded than the other. The 

 investigator soon learns to withhold final judgment, 

 realizing that the primary conditions for intellectual 

 development are the plasticity and openness of mind that 

 dogmatism and finality destroy. He knows that while 

 his researches may be, and indeed must be, iconoclastic, 

 they provide him with better icons in place of the old. 



Let us recall the steps in our progress through one and 

 another field of knowledge, from which representative 

 facts have been chosen for classification and summary. 

 We began with the basic principles of organic structure 

 and workings, and then we examined serially the larger 

 categories of the evidences relating to evolution as a 

 fact, and to the mode of its accomplishment by natural 

 factors. Proceeding to the special case of our own 

 species, we learned that human beings are inevitably a 

 part of nature and not outside it ; in structure, develop- 

 ment, and palseontological history, mankind is subject to 

 the control of the uniform laws which operate through- 

 out the entire range of living things. Finally, the men- 

 tal characters and the social relations of human organ- 

 isms were derived from beginnings lower down in the 

 scale, and were proved to be no more exceptional than 

 the physical constitution of a single human being. 



Are we to forget all of these things when we try to put 

 in order our ideas belonging to the categories of higher 

 thought? Can we hope to find the truth if we fail to 



