152 DOGMATISM AND EVOLUTION 



attained at a bound. The validity of scientific laws is not de- 

 pendent, to be sure, on the particular concrete use to which we 

 may choose to put them. But their significance and truth may 

 still be conditioned by the nature of the results which we expect 

 in general to derive from them. On what grounds, for example, 

 do we judge the validity of the principle of classical political 

 economy, that men seek to gratify their desires by the least 

 exertion? Most assuredly we should not judge it to be invalid, 

 because as a matter of fact we find exceptions to it. That men 

 often rush onward in their pursuit of a coveted prize without 

 pausing to choose the shortest way, that exertion once undergone 

 as a necessary means to some desired end may come to be desired 

 for its own sake, are facts which may very well be regarded as 

 negligible in this connection. What does determine the validity 

 of the principle as a law of economics is its general serviceableness 

 in the explanation of a certain class of human actions, namely, 

 commercial intercourse. How serviceable such a general prin- 

 ciple will prove to be, depends very largely upon the degree to 

 which the science has at any given time carried its analysis of 

 the particular phenomena with which it deals. As a science pro- 

 ceeds it becomes more ambitious. It is led to correct its general 

 laws, not by the mere finding of exceptions to them for the 

 exceptions as such might be treated simply as the operation of a 

 counter-tendency but because there is developed a more ade- 

 quate appreciation of the particular phenomena which the law 

 purports to correlate. Laws are revised, not because they are 

 false, but because they are shallow. This may very well be seen 

 in the recent history of the very case which we have just men- 

 tioned, the classical abstraction of the 'economic man.' The 

 truth of the conception of the 'economic man' is questioned 

 today, not because of its mere abstractness, but rather because 

 it is too rough and ready an affair for the purposes of present-day 

 economics. A more careful study of the operations of a market, 

 a finer analysis of the phenomena of supply and demand, a 

 deeper msight into the nature of value, due in part to investiga- 



