22 SCIENTIFIC METHOD 



original inductions and in subsequent deductions, and 

 add our tendency to begin our deductions with hypo- 

 theses in want of principles, we realize the importance 

 of verifying our conclusions. A curious example is 

 afforded by the present condition of the theory of Free 

 Trade, which Mill regarded as discovered and proved 

 by the verificatory method. Adam Smith had begun 

 with principles of human nature, such as that every man 

 is a better judge of his own interest than any legislator 

 can be for him, and had deduced a conclusion in favour 

 of as much liberty as is consistent with right. The 

 ultimate result was the partial adoption of Free Trade. 

 Now Mill regarded this conclusion as verified by the 

 prosperity of nations which had adopted this system. 

 But unexpectedly, since his time, some nations which 

 have remained protectionist have risen to great pros- 

 perity, especially in America and in Germany. What 

 seemed proved has become matter of doubt and dis- 

 pute. Not that Smith's conclusion has been proved 

 false. Theoretically, it was a general presumption in 

 favour of liberty from restrictions, deduced from premisses 

 immersed in the complex matter of human affairs, and 

 applicable only according to circumstances. In passing 

 into practice, it became an absolute dogma, the exaggera- 

 tions of which cannot be verified. The problem should 

 be referred back from politicians to philosophers, in order 

 to distinguish the limits within which the theory of Free 

 Trade is applicable, and capable of being verified by 

 historical facts without exception. 



We have reviewed some of the methods of science. 

 It appears that pure mathematical and pure empirical 

 methods are clearly defined but limited. Mixed method, 

 on the other hand, is far-reaching and complicated. 

 The part of the logician is to recognize its various ramifi- 



