THE WONDERS OP LIFE 



True philosophy, taken in this sense, may proudly 

 and justly style itself "the queen of the sciences." 



When philosophy, as a search for truth in the highest 

 sense, thus unites our isolated discoveries and seeks 

 to weld them into one unified system of the world, it 

 comes at length to state certain fundamental problems, 

 the answer to which varies according to the degree of 

 culture and the point of view of the inquirer. These 

 final and highest objects of scientific inquiry have been 

 of late comprehended under the title of The Riddle of 

 the Universe, and I gave this name to the work I pub- 

 lished in 1899, which dealt with them, in order to make 

 its aim perfectly dear. In the first chapter I dealt 

 briefly with what have been called "the seven great 

 cosmic problems," and in the twelfth chapter I en- 

 deavored to show that they may all be reduced to one 

 final "problem of substance," or one great "riddle of the 

 universe." The general formulation of this problem is 

 effected by blending the two chief cosmic laws — the 

 ebemical law of the constancy of matter (Lavoisier, 

 1789), and the physical law of the constancy of force 

 (Robert Mayer, 1842). This monistic association of the 

 two fundamental laws, and establishment of the unified 

 law of substance, has met with a good deal of agree- 

 ment, but also with some opposition; but the most 

 violent attacks were directed against my monistic 

 theory of knowledge, or against the method I followed 

 in seeking to solve the riddle of the universe. The only 

 paths which I had recognized as profitable were those 

 of experience and thought — or empirical knowledge and 

 speculation. I had insisted that these two methods 

 supplemented each other, and that they alone, under 

 the direction of reason, lead to the attainment of truth. 

 At the same time I had rejected as false two other much- 

 frequented paths which purported to lead directly to a 

 profounder knowledge, the ways of emotion and revela- 



