THE THEORY OF GRAVITATION. 157 



XXIX. 



I did not take undue credit to myself when as a child I rectified the 

 system taught by Lucretius and drew from it immediately its most 

 important consequences, for this was extremely easy or rather entirely 

 natural. Besides, I knew but little more the value and solidity of my 

 little views than the child ordinarily knows the wit or sense which we 

 find in its repartees and sallies. Indeed, the extremely simple idea of 

 trying to explain the principal natural phenomena by the aid of a sub- 

 tle fluid vigorously agitated in every direction has come to many writers 

 who have before presented it in a vague and ill-assured fashion, not to 

 mention that there has been without doubt a still greater number who 

 have not even deigned to communicate at all. I am well convinced that 

 since the law governing the intensity of universal gravitation is similar 

 to that for light, the thought will have occurred to many physicists 

 that an ethereal substance moving in rectilinear paths may be the 

 cause of gravitation, and that they may have applied to it whatever of 

 skill in the mathematics they have possessed. 



XXX. 



But we may say, How is it that none of these physicists have pushed 

 these consequences to their conclusion and communicated the research ? 



Doubtless because the most of them having no clear view of this 

 chaos (of which the first glance is, I admit, frightful) they have not 

 known how to disentangle it and subject it to their calculations. Or 

 not having firmly grasped the principles of the theory, they have 

 allowed themselves to be seduced by specious sophisms, by which men 

 have pretended to refute in advance all imaginable explanations of 

 gravitation. Or they will have had the foible of bowing to the author- 

 ity of great names, when it is alleged (whether justly or falsely) that 

 they have pronounced upon the impossibility of this or upon the use- 

 lessness of that branch of knowledge. Or they have lacked sufficient 

 love of truth or courage of their convictions to abandon easy pleasures 

 and exterior advantages in order to devote themselves simply to 

 researches at the time difficult and little welcome. Or, finally, they 

 have failed to become impressed with the strength and fecundity of 

 this beautiful system so distinctly as to lead them, in their enthusiasm, 

 to sacrifice to it their other views and projects. " 



Appendix. 



Constitutions which I assign to heavy bodies and to the gravitational 

 fluid; followed by a mathematical conception and some remarks to fix 

 the ideas of geometers who desire to follow out for themselves the con- 

 sequences of this mechanism, and who may desire first to know pre- 

 cisely what are the hypotheses from which I claim all the phenomena 

 to follow necessarily. 



