48 PASTEUR: THE HISTORY OF A MIND 



seen in the light of Pasteur's work. What kind of a 

 world would it be in which one would replace the cellu- 

 lose and albumen in the actually living cells by their 

 opposites and, to recall to our minds that which we 

 have already gone over, what kind of a world would it be in 

 which the earth should turn around the sun in a direction 

 opposite to that which it now takes, an earth where the 

 electric current which makes of it a magnet should take 

 an opposite direction and where the point of the compass 

 needle which marks the north should mark the south? 



We are right in thinking that it would be a world not 

 identical with the actual world. We may even believe 

 that it would differ very much, and behold therein the 

 profound thought of Pasteur, the bond which unites 

 our nature to cosmic phenomena. We are all the 

 children of the sun, as someone has said, speaking from 

 another viewpoint. We see here more than that. The 

 sun not only distributes the force, but it influences its 

 direction and its use. 



We see also, at the same time, all the difficulty which 

 one would encounter in approaching the problem by 

 experiment. In order to introduce into a cell proxi- 

 mate principles different and opposite from those which 

 exist there, it would be necessary to act upon it at the 

 time of its greatest plasticity, that is, to take the germ 

 cell and try to modify it. But this cell has received 

 from its parents a heredity in the form of one or several 

 active substances, the presence of which is sufficient 

 to render it rebellious to certain actions and to make it 

 accept others, that is to say, to impart to its evolution 

 a definite direction. This cell contains in the beginning 

 not only its being but also its becoming, and it is therefore 

 an initial force which augments without ceasing by giving 

 its own direction to new forces which appear every 

 day in the little world it governs. Vires acquirit eundo. 



