SPREAD OF UNDERSTANDING / 



were put down in Roman letters, the calculations themselves were 

 lost in the sand or vanished with the motions of the counters. 



The heroic period was now long over and the rest of the history 

 of our numerals is but one example, among so many others, of the 

 difficulty of overcoming the enormous inertia of vested tradi- 

 tions. The case is interesting because the new decimal system 

 was a time- and labor-saving invention of the first magnitude. 



The Hindus had made to mankind a gift of inestimable value. 

 No strings of any kind were attached to it, nor was the sug- 

 gested improvement entangled with any sort of religious or philo- 

 sophic ideas. Those proposing to use the new numerals were not 

 expected to make any disavowal or concession; nor could their 

 feelings be hurt in any way. They were asked simply to exchange 

 a bad tool for a good one. Yet it was not until the fourteenth and 

 fifteenth centuries that the new system was generally accepted in 

 Italy, and not until the sixteenth and even the beginning of the 

 seventeenth that it was finally established in the rest of civilized 

 Europe. 



All counted, more than a millennium had elapsed between the 

 discovery and its general acceptance, even in that primary stage. 

 In the meanwhile, it is true, the center of civilization had moved 

 from Southern Asia to Western Europe, but that had not been the 

 cause of the delay. Mountains and seas and even desert plains are 

 smaller obstacles to the diffusion of ideas than the unreasonable 

 obstinacy of man. The main barriers to overcome are not out- 

 side, but inside the brain. 



7he Second Story (which is very different, and yet not so dif- 

 ferent). It is well known that the circulation of the blood in the 

 human body was satisfactorily explained for the first time by Wil- 

 liam Harvey. The first idea of this discovery occurred to him not 

 later than 1616 but he did not publish it until 1628 in a little book 

 dealing with the motion of the heart and blood. One is rather sur- 

 prised to find that this book did not make more stir; neither did it 

 arouse much opposition, at least in England. In France the oppo- 



