356 POPULAR SCIENCE MONTHLY 



planets to follow; he made velocity increase proportionally to the time 

 in falling bodies ; he made the laws of the sines for light to obey when 

 refracted; he established the classes, orders, families and genera of 

 plants and animals, and fixed the distances between them. He thought 

 the archetypes of all things, and devised their variations; and when we 

 re-discover any one of these his wondrous institutions, we seize his mind 

 in its very literal intention. 



But as the sciences have developed farther, the notion has gained 

 ground that most, perhaps all, of our laws are only approximations. 

 The laws themselves, moreover, have grown so numerous that there is 

 no counting them; and so many rival formulations are proposed in all 

 the branches of science that investigators have become accustomed to 

 the notion that no theory is absolutely a transcript of reality, but 

 that any one of them may from some point of view be useful. Their 

 great use is to summarize old facts and to lead to new ones. They 

 are only a man-made language, a conceptual shorthand, as Pearson 

 calls them, in which we write our reports of nature; and languages, as 

 is well known, tolerate much choice of expression and many dialects. 



Thus human arbitrariness has driven divine necessity from scien- 

 tific logic. If I mention the names of Sigwart, Mach, Ostwald, Pear- 

 son, Milhaud, Poincare, Duhem, Heymans, those of you who are stu- 

 dents will easily identify the tendency I speak of, and will think of 

 additional names. 



Hiding now on the front of this wave of scientific logic Messrs. 

 Schiller and Dewey appear with their pragmatistic account of what 

 truth everywhere signifies. Everywhere, these men say, ' truth ' in 

 our ideas and beliefs means the same thing that it means in science. 

 It means, they suggest, nothing but this, that ideas become true just in 

 so far as they help us to get into satisfactory relation with the other 

 parts of our experience, to synthesize and summarize facts and other 

 ideas, and get about among them by conceptual short-cuts instead of 

 following the interminable labyrinth of particular phenomena as they 

 succeed one another. Any idea upon which we can ride, so to speak; 

 any idea that will carry us prosperously from any one part of our 

 experience to any other part; linking things satisfactorily, working 

 securely, simplifying, saving labor, is true for just so much, true in so 

 far forth, true instrumentally. This is the ' instrumental ' view of 

 truth taught so successfully at Chicago, the view that truth means the 

 power of our ideas to ' work,' promulgated so brilliantly at Oxford. 



Messrs. Dewey, Schiller and their allies, in reaching this general 

 notion of all truth, have only followed the example of geologists, 

 biologists and philologists. In the establishment of these other sci- 

 ences, the successful stroke was always to take some simple process 

 actually observable in operation — as denudation by weather, say, or 



