Introduction 1 7 



XV 



•I suggest then that in scientific research it is a wise procedure 

 to press " mechanical " theories of the material world to their 

 utmost limits. Were I, for example, a biologist I should endeavour 

 to explain all the phenomena under investigation in terms of matter 

 and motion. I should always be searching for what could be 

 measured and calculated, however confident I might be that in 

 some directions at least the hopeless limitations of such a view 

 would very rapidly become apparent. 



In the practice of life, on the other hand, and in the specula- 

 tion of philosophy, we are free to move within wider horizons. 

 In forming our estimate of the sort of beliefs which may properly 

 be regarded as rationally acceptable, we ought not to be limited by 

 mechanistic pre-suppositions, however useful these may be in our 

 investigations of nature. We are spiritual beings, and must take 

 account of spiritual values. The story of man is something more 

 than a mere continuation of the story of matter. It is different 

 in kind. If we cannot calculate the flow of physical events, 

 that is because our knowledge of natural processes is small, and 

 our power of calculation feeble. If we cannot calculate the course 

 of human history, that is because (among other reasons) it is in- 

 herently incalculable. No two specimens of humanity exactly 

 resemble each other, or live in circumstances that are exactly 

 comparable. The so-called " repetitions " of history are never 

 more than vague resemblances. The science of history therefore, 

 if there be one, is something quite different from (say) the science 

 of physics. And this is true even when history is wholly divorced 

 from religion. But when it is considered in a different setting, 

 when man is regarded as a spiritual agent in a world under spiritual 

 guidance, events of spiritual significance cannot be wholly judged 

 by canons of criticism which seem sufficient for simpler cases. 

 Unexampled invasions of the physical sphere by the spiritual are 

 not indeed to be lightly believed. But they are certainly not 

 to be rejected merely because historians cannot bring themselves 

 to accept the " miraculous." 



