The Evolution of the Sciences 



But there are also men who, without being bound 

 to a system, or seeking the eternal truths, try 

 only to create a little light around them. They 

 think that methodical and scientific investigation 

 will bring them the only truth which they can 

 attain; they ask from science neither recipes 

 nor arguments; they seek the satisfaction of 

 natural curiosity and the pleasure of under- 

 standing how the chaos of facts is organised 

 gradually by the efforts of scientists. It is for 

 such that this book has been written. I have 

 tried to show them how the sciences shed light 

 over an ever- widening circle. After having 

 analysed the facts which are directly accessible 

 to our senses, they make known to us others 

 which had escaped them; like these rays which 

 traverse bodies and show us their bony frame- 

 work, they peer to the depths of the universe 

 and teach us its extraordinary complexity. 

 But they reveal to us law and harmony. Scientific 

 progress is the product of this incessant ran- 

 sacking of the unknown world, and of the co- 

 ordination which every day becomes more close, 

 of the facts acquired. 



At the same time the Unity of Science 



