410 



SCIENCE 



[N. S. Vol. XLIV. No. 1134 



actions. Both have their bad sides; there 

 are evil ends directing actions, and there 

 are ignoble curiosities of the understanding. 



The importance, even in practise, of the 

 theoretical side of science arises from the 

 fact that action must be immediate, and 

 takes place under circumstances which are 

 excessively complicated. If we wait for 

 the necessities of action before we com- 

 mence to arrange our ideas, in peace we 

 shall have lost our trade, and in war we 

 shall have lost the battle. 



Success in practise depends on theorists 

 who, led by other motives of exploration, 

 have been there before, and by some good 

 chance have hit upon the relevant ideas. 

 By a theorist I do not mean a man who is 

 up in the clouds, but a man whose motive 

 for thought is the desire to formulate cor- 

 rectly the rules according to which events 

 occur. A successful theorist should be ex- 

 cessively interested in immediate events, 

 otherwise he is not at all likely to formulate 

 correctly anything about them. Of course, 

 both sources of science exist in all men. 



Now, what is this thought organization 

 which we call science? The first aspect of 

 modern science which struck thoughtful 

 observers was its inductive character. The 

 nature of induction, its importance, and 

 the rules of inductive logic have been con- 

 sidered by a long series of thinkers, espe- 

 cially English thinkers, Bacon, Herschel, 

 J. S. Mill, Venn, Jevons and others. I am 

 not going to plunge into an analysis of 

 the process of induction. Induction is 

 the machinery and not the product, and it 

 is the product which I want to consider. 

 "When we understand the product we shall 

 be in a stronger position to improve the 

 machinery. 



First, there is one point which it is neces- 

 sary to emphasize. There is a tendency in 

 analyzing scientific processes to assume a 

 given assemblage of concepts applying to 



nature, and to imagine that the discovery 

 of laws of nature consists in selecting by 

 means of inductive logic some one out of a 

 definite set of possible alternative relations 

 which may hold between the things in na- 

 ture answering to these obvious concepts. 

 In a sense this assumption is fairly correct, 

 especially in regard to the earlier stages of 

 science. Mankind found itself in posses- 

 sion of certain concepts respecting nature — 

 for example, the concept of fairly perma- 

 nent material bodies — and proceeded to 

 determine laws which related the corre- 

 sponding percepts in nature. But the for- 

 mulation of laws changed the concepts, 

 sometimes gently by an added precision, 

 sometimes violently. At first this process 

 was not much noticed, or at least was felt 

 to be a process curbed within narrow 

 bounds, not touching fundamental ideas. 

 At the stage where we now are, the formula- 

 tion of the concepts can be seen to be as 

 important as the formulation of the empir- 

 ical laws connecting the events in the uni- 

 verse as thus conceived by us. For ex- 

 ample, the concepts of life, of heredity, of 

 a material body, of a molecule, of an atom, 

 of an electron, of energy, of space, of time, 

 of quantity, and of number. I am not dog- 

 matizing about the best way of getting such 

 ideas straight. Certainly it will only be 

 done by those who have devoted them- 

 selves to a special study of the facts in ques- 

 tion. Success is never absolute, and prog- 

 ress in the right direction is the result of 

 a slow, gradual process of continual com- 

 parison of ideas with facts. The criterion 

 of success is that we should be able to for- 

 mulate empirical laws, that is, statements 

 of relations, connecting the various parts 

 of the universe as thus conceived, laws with 

 the property that we can interpret the 

 actual events of our lives as being our frag- 

 mentary knowledge of this conceived inter- 

 related whole. 



