February 21, 1913] 



SCIENCE 



28S 



cism and agnosticism with regard to all 

 human knowledge. The rather should this 

 study serve as a reminder, how uncertain 

 and slow is the laying of solid foundations 

 for the building of the temple of science; 

 but also, how solid those foundations, when 

 well laid, actually are ; and how noble the 

 temple which man is erecting toward the 

 skies, on these same foundations. 



Among a certain class of psychologists 

 and philosophers — I am ashamed to confess 

 it — there has been much deprecating and 

 even sneering, directed toward the stern 

 control of the logical faculties in the dis- 

 covery and proof of the nature of reality. 

 "The will to believe," or the leap of emo- 

 tion to conclusions affecting the nature of 

 reality, has been attractively offered, and 

 far too freely accepted, as a substitute in 

 science as well as in religion, for the use 

 of reason under the control of reason's 

 lawful working. But the study of man 

 utters a loud warning against all this. 

 Even a truly scientific mind may express 

 itself and its findings in an alluring rhe- 

 torical style. But such a style can never 

 be safely trusted as evidence for, however 

 effective it may prove in exposition of, the 

 truths of either common life or science and 

 philosophy. Logic may be fervid, but it 

 must still remain logic, if it is to be offered 

 in proof of truth. On the one hand, it is 

 true that a purely logical or dialectical 

 construction of scientific theory, after the 

 Platonic or the Hegelian method, when it 

 cuts itself from the bonds which tie it down 

 to concrete facts of more or less nearly 

 universal experience, is not man's way to 

 measure most faithfully the truth of things. 

 But, on the other hand, it is equally the fact 

 that only by the use of the intellect, the 

 logical or so-called dialectical faculty, can 

 the truth be explicated and interpreted as 

 it lies hidden in the facts. The history of 

 scientific progress shows beyond all ques- 



tion, that it is not great collectors of facts, 

 but great thinkers reasoning concerning the 

 meaning of the facts, who have most con- 

 tributed to this progress. 



An additional consideration of no small 

 importance which is made quite clear by 

 the natural history of the individual mind, 

 as well as by the natural history of the 

 race, is this : Knowledge is not only a mat- 

 ter of development, of progressive achieve- 

 ment, in the individual and in the race; it 

 is also a matter of degrees. Any body of 

 knowledge, no matter how strictly it may 

 be entitled to the term science, will neces- 

 sarily consist of propositions that are made 

 with quite different degrees of assurance. 

 This truth should always be frankly ac- 

 knowledged in the methodical procedure of 

 every science. Every positive science will, 

 of course, aim to have its different concep- 

 tions, so-called laws, and fundamental 

 principles hang well together. It will also 

 attempt to fortify itself by coming into 

 relations of mutual support with the other 

 most nearly allied sciences. It will, above 

 all, test its own conclusions by the amount 

 of agreement which its own best students 

 and trained experts have been able to 

 reach as exponents of the best intellects of 

 the race, in their prolonged and unpi-eju- 

 diced application to the problem of inter- 

 preting the experience of the race. But 

 every science will also remember that the 

 very method of science, as inexorably fixed 

 by the nature of man's intellectual proc- 

 esses, makes it necessary to discriminate 

 different degrees of knowledge, with shift- 

 ing degrees of certainty and changing 

 claims to importance, as the knowledge of 

 the race advances in clearness and com- 

 prehension. 



In this connection it is worth while 

 simply to call attention to the fact that the 

 mental attitudes of scepticism, criticism 

 and agnosticism are indispensable and val- 



