96 Life and Matter [chap. v. 



already known facts necessarily seems to cor- 

 respond, or have close affinity, with the truth. It 

 is the result of experience of a mathematical 

 theorem concerning unique distributions. For 

 instance, it can be shown that in an electric field, 

 however complicated, any distribution of potential 

 which satisfies boundary conditions, and one or two 

 other essential criteria, must be the actual 

 distribution ; for it has been rigorously proved 

 that there cannot be two or more distributions 

 which satisfy those conditions, hence if one is 

 arrived at theoretically, or intuitively, or by any 

 means, it must be the correct one ; and no further 

 proof is required. 



So, also, in connection with analogies and work- 

 ing models : although they must necessarily be 

 imperfect, so long as they are only analogies, yet 

 the making or imagining of models (not neces- 

 sarily or usually a material model, but a conceptual 

 model) is a recognised way of arriving at an 

 understanding of recondite and ultra-sensual 

 processes, occurring say in the ether or elsewhere. 

 As an addition to evidence derived from such 

 experiments as have been found possible, and as a 

 supplement to the experience out of which, as out 

 of a nucleus, every conception must grow, the 

 mind is set to design and invent a self-coherent 

 scheme which shall imitate as far as possible the 



