METHOD IN SCIENCE 7 



experiments or observations that may lead to more general 

 conclusions," there is no need to push it to an absurd 

 extreme, as Herbert Spencer himself did, when he endorsed 

 Liebig's comparison of blood corpuscles, as a circulating 

 medium, to money. But from one point of likeness we may 

 proceed to two or three, or as many as we will, until there 

 is complete identity in all essentials. To dismiss an 

 analogy, in which there are many points of resemblance, as 

 pure fancy is unwise, to say the least of it, since it stimulates 

 the imagination in the liveliest way. Most advances in 

 thought are made by the imaginative, who yet hold steadily 

 to the view that the most ingenious hypothesis cannot 

 become theory unless it is in accordance with the greater 

 general laws of the more inclusive sciences, and at last 

 enables us to prophesy about unknown phenomena, and 

 to put into order disconnected facts. Used in this way 

 the discovery of suggestive analogies is the parent of real 

 progress, and it ought not to be necessary to say so. If it 

 were not necessary we should see the method used, and 

 students, young or old, would not be so greatly burdened 

 with mere isolated observations. 



If, then, we admit that general laws are everywhere the 

 same in their working, however much obscured by the com- 

 plexities of the less inclusive sciences, and allow that 

 analogies tried by such laws are a legitimate field for the 

 scientific imagination, we must conclude that observed 

 sequences in one science ought to be discoverable in all 

 others. And if certain sequences are clear in one and 

 obscure in another, while there are still sufficient points of 

 likeness to suggest a like kind of explanation in the obscure 

 set, we may legitimately conclude that we are face to face 

 with the same general laws. 



To illustrate such points is not altogether easy, since 



