PRINCIPLES AND METHODS 109 



events. But on the one hand it is not always easy to 

 discover the really efficacious rite, and on the other 

 hand, the desired result always remains uncertain since 

 it depends on the good will of the spirits. The scientific 

 and rational mind proceeds otherwise. In its concep- 

 tion the relation which unites one sensible phenomenon 

 to another, such as a cause to its effects, is constant. 

 Hence, this relation once discovered, the phenomena 

 and the resulting consequences can be made use of 

 with certainty. 



Strange as it may appear, it is much easier to inter- 

 pret natural phenomena according to the pre-scientific 

 mind than according to the rational mind. 1 The 

 actions and reactions which take place in nature are 

 so complex and so varied that research into causes 

 and laws in the scientific sense is extraordinarily diffi- 

 cult and arduous. In fact, no people except the Greeks 

 have attempted it. The Hindoos, for example, in spite 

 of their very advanced civilization, have never in their 

 reasoning gone beyond the stage of the pre-scientific 

 mentality. The flux of sensations which creates in us 

 the image of the perceptible world does not, according 

 to them, obey constant and fixed laws ; it cannot give 

 birth to a science, properly so called. Ancient Greece 

 has had the genius and audacity to conceive that the 

 matter on which our mental activity is exercised is 

 subject to determinate relations. It has formed the 

 opinion that these relations could not exist without 

 a community of nature between the terms of which 

 they are constituted : the effect must have some 

 resemblance to the cause which produces it. It is 



1 M. Jean Piaget has just published a book which is very 

 suggestive on this point, Le langage et la pensee chez V enfant. 

 Delachaux and Nietsle, Neuchatel, 1923. This book, original 

 in its method and results, shows in particular how, in the 

 child, scientific notions are gradually and with difficulty 

 substituted for pre-scientific and egocentric ideas. 



