74 BIOLOGICAL LECTURES. 



science. Forces dethroned, and matter indestructible, that is 

 the result of the scientific activity of the past half century. 



When one contemplates that proposition, and thinks of the 

 wonderful variety of phenomena in the earth and in the 

 heavens, and then attempts to realize even in a faint way how 

 all this can possibly come about through the sole agency of 

 motions of any kind, however complex in their combinations, he 

 cannot but feel there must somehow and somewhere be an 

 undetected slip in the logic, or there must be a factor, and a 

 most important factor, left out ; for at some time in the history 

 of things, at any rate on the earth, there have appeared not only 

 living things as plants and animals, but activities of another 

 class, feelings and intelligence. Along with physical happen- 

 ings and physical things there has come the senses and the 

 intellect, the possibility of pleasure, the consciousness and 

 delight in existence, hopes and fears, and other phenomena, 

 which cannot by any jugglery of idea or language be resolved 

 into molecular vibrations or rotations, or any other motions 

 whatever. They are the things we live for, and care to live 

 for. These qualities we find in experience to be always associ- 

 ated with matter and various forms of energy; but the character 

 of the two classes of phenomena appears so different as to have 

 led philosophers to the conclusion that they could exist apart, 

 having no necessary relation to each other ; indeed, the terms 

 "matter" and "mind" are generally set against each other as 

 contrasting things which have nothing in common. Matter 

 has been called dead, inert, and incapable of doing anything 

 except when other agencies as forces have acted upon it, while 

 mind has been believed to be the source of life and endowed 

 with inherent energy. What is energy ? The books do not 

 make it clear. To say it is ability to do work is not to define 

 it, but to tell what it can do. Wind, water, steam, electricity, 

 a horse may do work, but no one of them is energy; and energy 

 is riot known in experience when disembodied, that is, outside 

 of some substantial thing, and then only shows itself in the 

 degree and kind of activity of that thing. It is in all of our 

 experiences an exchangeable commodity, but there is never an 

 exchange except a mass of matter of some degree of magnitude 



