45o POPULAR SCIENCE MONTHLY 



on their interpretation. It is just on that account that they were 

 obliged to have recourse to procedures of discussion so unscientific. 



This is why I think they did not disagree about a fact: we have 

 not the right to give the same name to the rotation of the earth, which 

 was the object of their discussion, and to the facts crude or scientific 

 we have hitherto passed in review. 



After what precedes, it seems superfluous to investigate whether the 

 fact in the rough is outside of science, because there can neither be 

 science without scientific fact, nor scientific fact without fact in the 

 rough, since- the first is only the translation of the second. 



And then, has one the right to say that the scientist creates the 

 scientific fact? First of all, he does not create it from nothing, since 

 he makes it with the fact in the rough. Consequently he does not 

 make it freely and as he chooses. However able the worker may be, his 

 freedom is always limited by the properties of the raw material on 

 which he works. 



After all, what do you mean when you speak of this free creation 

 of the scientific fact and when you take as example the astronomer 

 who intervenes actively in the phenomenon of the eclipse by bringing 

 his clock ? Do you mean : The eclipse happened at nine o'clock ; but if 

 the astronomer had wished it to happen at ten, that depended only on 

 him, he had only to advance his clock an hour? 



But the astronomer, in perpetrating that bad joke, would evidently 

 have been guilty of an equivocation. When he tells me: The eclipse 

 happened at nine, I understand that nine is the hour deduced from 

 the crude indication of the pendulum by the usual series of correc- 

 tions. If he has given me solely that crude indication, or if he has 

 made corrections contrary to the habitual rules, he has changed the 

 language agreed upon without forewarning me. If, on the contrary, 

 he took care to forewarn me, I have nothing to complain of, but then 

 it is always the same fact expressed in another language. 



In sum, all the scientist creates in a fact is the language in which 

 he enunciates it. If he predicts a fact, he will employ this language, 

 and for all those who can speak and understand it, his prediction is 

 free from ambiguity. Moreover, this prediction once made, it evi- 

 dently does not depend upon him whether it is fulfilled or not. 



What then remains of M. LeEoy's thesis? This remains: the 

 scientist intervenes actively in choosing the facts worth observing. 

 An isolated fact has by itself no interest; it becomes interesting if one 

 has reason to think that it may aid in the prediction of other facts; 

 or better, if, having been predicted, its verification is the confirma- 

 tion of a law. Who shall choose the facts which, corresponding to 

 these conditions, are worthy the freedom of the city in science? This 

 is the free activity of the scientist. 



