66 Introduction 



doing they only reveal their ignorance and arrogance. Men of science 

 have a better right to be proud of the growth of science, but the greatest 

 of them are singularly humble, for they realize that much as has been 

 done, much more remains to be done. The universe is infinitely mys- 

 terious. Light and charity are increasing in some places, but there is 

 still an abundance of darkness, injustice, and suffering. Great wars are 

 not only material calamities, they are fantastic retrogressions. Every 

 good scientist is so far from boasting that he would rather walk in sack- 

 cloth and ashes. Though he may say to himself that the inventor of 

 new tools cannot be held responsible for the misuses of them by men 

 of prey, he is not quite convinced of that. He is, perhaps, more guilty 

 than he thinks, and in any case he prefers to assume more guilt rather 

 than less. 



It is certain that whatever spiritual progress we may be privileged to 

 enjoy, it is due less to our own efforts than to the accumulated efforts of 

 our ancestors. Should we forget that and become too pleased with our- 

 selves, we would soon fall into scepticism and cynicism. Indeed, we 

 are never so much in danger of losing our spiritual freedom as when we 

 boast too much of it. Nobody can teach men of science better than the 

 historian of science the need of reverence for the past, humility for the 

 present, confidence in the future; nobody can give him more strength to 

 follow his path honestly and courageously, to bear evil and suffering, to 

 do his best to alleviate them, to find and publish the truth. 



