324 INDUCTION. 



Induction, which it is of real importance to clear up, because 

 the theory of Induction has heen, in no ordinary degree, con 

 fused hy it, and because the confusion is exemplified in the 

 most recent and elaborate treatise on the inductive philosophy 

 which exists in our language. The error in question is that 

 of confounding a mere description, by general terms, of a set 

 of observed phenomena, with an induction from them. 



Suppose that a phenomenon consists of parts, and that 

 these parts are only capable of being observed separately, and 

 as it were piecemeal. When the observations have been made, 

 there is a convenience (amounting for many purposes to a 

 necessity) in obtaining a representation of the phenomenon as 

 a whole, by combining, or as we may say, piecing these 

 detached fragments together. A navigator sailing in the 

 midst of the ocean discovers land : he cannot at first, or 

 by any one observation, determine whether it is a continent 

 or an island ; but he coasts along it, and after a few days finds 

 himself to have sailed completely round it : he then pronounces 

 it an island. Now there was no particular time or place of 

 observation at which he could perceive that this land was 

 entirely surrounded by water : he ascertained the fact by a 

 succession of partial observations, and then selected a general 

 expression which summed up in two or three words the 

 whole of what he so observed. But is there anything of the 

 nature of an induction in this process ? Did he infer anything 

 that had not been observed, from something else which had ? 

 Certainly not. He had observed the whole of what the pro 

 position asserts. That the land in question is an island, is 

 not an inference from the partial facts which the navigator saw 

 in the course of his circumnavigation ; it is the facts them 

 selves ; it is a summary of those facts ; the description of a 

 complex fact, to which those simpler ones are as the parts of 

 a whole. 



Now there is, I conceive, no difference in kind between this 

 simple operation, and that by which Kepler ascertained the 

 nature of the planetary orbits : and Kepler s operation, all 

 at least that was characteristic in it, was not more an inductive 

 act than that of our supposed navigator. 



