SEVENTEENTH AND EIGHTEENTH CENTURIES ^2.3 

 Newton and, either through him or directly also, from Galileo; at any rate, 

 he here displays an insight into both the aims and the limitations of natural 

 science that few scientists before his age possessed and that many have lacked 

 even in our own time. 



His history of the earth 

 BuFFON, having thus given an account of the general principles on which 

 naturalists should work, proceeds to give a theory of the earth and its de- 

 velopment into a habitation for living creatures. This problem was mani- 

 festly of very great interest to him; in fact he has dealt with it repeatedly — 

 in an essay at the beginning of this great work, called "Theorie de la terre," 

 and in another, more extensive essay, written considerably later, entitled 

 "Des epoques de la nature." In this sphere, it is true, he had precursors; Steno, 

 whose geological works have been mentioned previously, Ray, who wrote 

 a treatise on the changes in the earth, and, the greatest genius of them all, 

 Swedenborg;^ but Buffon must nevertheless be mentioned as the first who 

 thought to investigate the earth's history with special reference to the 

 development of living creatures. 



Moreover, in his latter work he had the temerity to reject the biblical 

 six-thousand-year age of the world and to attribute to the earth a far higher 

 age — certainly small in comparison with the length of the epochs which 

 modern geology assumes, but at least entailing a break with the till then 

 incontrovertible theory of the creation — a break induced by the impossi- 

 bility of fitting the geological and biological evolution on the earth within 

 such a short space of time as six thousand years. Steno had already faced this 

 dilemma, but, pious Catholic as he was, he preferred to abandon geology 

 rather than Church doctrine; BufFon courageously took the step in spite of 

 his previous contretemps with the French theologians. Even as early as in his 

 "Theorie de la terre" he expounds his ideas as to the origin of the earth, 

 expressly emphasizing, however, their purely hypothetical character. He as- 

 sumes, in agreement with Leibniz, that the earth evolved from an incandes- 

 cent state, but while the latter believed that the earth itself had from the 

 beginning been a "sun," Buffon derives it from the sun's mass, assuming that 

 once upon a time a comet collided with the sun, with the result that pieces 

 broke off which gave rise to the earth and the other planets. This hypothesis 

 has often been cited as a proof of Buffon' s extravagant imagination; really, 

 it is no more eccentric than many contemporary cosmogonies, in which 

 comets in general quite often played a part, and in fact Buffon's is presented 

 with much more reservation than the others. After the incandescent state 

 there followed a period when the seas covered the earth, when the tide 

 exercised great influence upon earth-formation. As a proof of this theory of 



^ Buffon is said to have known Swedenborg's cosmological theories; he never quotes 

 them, however, though he does quote Steno and Ray and some other, less important authors. 



