158 UNIVERSAL EVOLUTION 



ter, is not merely mechanical movement, by change 

 of position, of many round atoms of substance. It is 

 the function of the structure. The molecules of matter 

 that makes up the tissues of living bodies, are the 

 storage batteries of energy, transformed from the 

 animal and vegetable food, taken into the diges- 

 tive apparatus; and molecular motion in the nerve 

 tissue means that this energy is being released by 

 catabolism. in the form of psychic phenomena; that is, 

 transformed into thought and ideas. Materialists call 

 this a physical process, while idealists call it an inde- 

 pendent process. Idealists contend that the result, 

 thought, or ideas, is the cause of the phenomenon, 

 while realists assert that the physiology of the living 

 matter produces the phenomenon. It is really the 

 escape, by the destruction of the proteid molecule, or 

 cell, of the stored energy, or retained motion, which 

 has been metamorphosed from other animals or vege- 

 tables, in the form of food, by the human being. This 

 destruction of nerve tissues is followed, or accompanied 

 by, an observed psychical phenomenon, which is varia- 

 bly called thought, idea, image, conception, imagina- 

 tion, or memory. Those molecules of matter thus 

 destroyed, are quickly replaced in the living organism, 

 from the blood, by a process called anabolism. the 

 whole process, of destruction and construction, is meta- 

 bolism. As said elsewhere, the body is a maelstrom of 

 active energy, the explosions of atoms, or centers of 

 energy giving the effects. All the mental and physical 

 activity of the organism depends upon this physiologi- 

 cal process, and ceases entirely when the metabolism 

 stops. 



Hnxley, in commenting on Hume's contention, that 

 thought is produced by the physiology of the brain, 



