280 THE POPULAR SCIENCE MONTHLY 



that individual development or ontogeny repeats in a general way race 

 development or phylogeny. The designation and systematization and 

 organization of sense impressions, on the one hand, and subjective states 

 on the other, which are the very essence of rational life, and which dis- 

 tinguish the civilized man from the savage, and the adult from the 

 child, are found on closer examination to consist fundamentally, as to 

 fully one half at least, in naming and placing and correlating the attri- 

 butes of natural objects. 



Turning now from the racial and the individual development of ordi- 

 nary rational life, to the development of physical science, we may char- 

 acterize this development by saying that its whole course has been one 

 of discovery of new natural bodies each having its own attributes; and of 

 new attributes of old bodies, that is, of bodies already known. 



The attributes of bodies, with many for each body, are the very 

 cement and sand and gravel and steel out of which the reinforced con- 

 crete edifices of experiential knowledge, both common and scientific, are 

 built up ; and any one who comes forward with a hypothesis of nature 

 which in essence declares that some single one of these building mate- 

 rials is all that nature really furnishes so that the edifice of knowledge 

 must get along with only this one, is presenting a daring hypothesis 

 sure enough. If true it must, of course, be accepted ; but no one should 

 fail to see that its complete acceptance would mean the complete demoli- 

 tion of the great edifices of common knowledge and physical science as 

 these have been laboriously built up through the centuries, and the erec- 

 tion on their sites of other edifices wholly different in design and con- 

 struction. Surely the proof in support of so revolutionary a hypothesis 

 must be convincing beyond a shadow of doubt. Is it? For one I am 

 convinced it is not. Were there no other grounds for doubting the elec- 

 trical theory of matter and so of all nature, a sufficient one is found in 

 the circumstance already alluded to, namely that no physical observa- 

 tion or experiment ever gets rid of the " probable error " ; and that in 

 this probable error there is always a chance of an unknown factor in the 

 phenomena under investigation. 



So I turn again to the natural history way of viewing the world and 

 point out that it is in strict accord with both the historic development of 

 natural knowledge and the fundamental processes of psychic life in that 

 it accepts without cavil the whole range of attributes of natural bodies, 

 demanding only that these be undoubted as to identification. It is only 

 when the natural history attitude and the materialistic attitude toward 

 nature is each viewed in its mode of treating the attributes of natural 

 objects, that the fundamental distinction between the two attitudes 

 comes to view. The natural history attitude is one of unreserved accept- 

 ance of the world of fact, one of its greatest concerns being to make sure 

 of what the facts are. It makes no such sharp distinction between fact 



