CONCEPTION. 467 



lock the parts. In this case, nobody would pretend that 

 the richer and more elaborate conception which we gain 

 of the puzzle after solving it came directly out of our first 

 crude conception of it, for it is notoriously the outcome of 

 experimenting with our hands. It is true that, as they 

 both mean that same puzzle, our earlier thought and our later 

 thought have one conceptual function, are vehicles of one 

 conception. But in addition to being the vehicle of this 

 bald unchanging conception, ' that same j^uzzle,' the later 

 thought is the vehicle of all those other conceptions which 

 it took the manual experimentation to acquire. Now, it is 

 just the same where the whole is mathematical instead of 

 being mechanical. Let it be a polygonal space, which we 

 cut into triangles, and of which we then affirm that it is 

 those triangles. Here the experimentation (although usu- 

 ally done by a pencil in the hands) may be done by the 

 unaided imagination. We hold the space, first conceived 

 as jjolygonal simply, in our mind's e^-e until our atten- 

 tion wandering to and fro within it has carved it into the 

 triangles. The triangles are a new conception, the result of 

 this new operation. Having once conceived them, however, 

 and compared them with the old polygon which we origi- 

 nally conceived and which we have never ceased concei^-iug, 

 we judge them to fit exactly into its area. The earlier and 

 later conceptions, we say, are of one and the same space. 

 But this relation between triangles and polygon which the 

 mind cannot help finding if it compares them at all, is very 

 badly expressed by saying that the old conception has de- 

 veloped into the new. New conceptions come from new 

 sensations, new movements, new emotions, new associations, 

 new acts of attention, and new comparisons of old concep- 

 tions, and not in other ways, Endogenous prolification 

 is not a mode of growth to which conceptions can lay 

 claim. 



I hope, therefore, that I shall not be accused of hud- 

 dling mysteries out of sight, when I insist that the psychol- 

 ogy of conception is not the place in which to treat of those 

 of continuity and change. Conceptions form the one class 

 of entities that cannot under any circumstances change. 

 They can cease to be, altogether ; or they can stay, as what 



