32 POPULAR SCIENCE MONTHLY 



Probably the contribution of evolutionary theory to our knowledge of 

 mind that bulks larger than any other is the discovery, growing clearer 

 with each year of study, that the human mind also is fundamentally 

 just a group of activities, greatly complicated, mysteriously unified, 

 wonderfully resourceful, marvelously progressive, self-conscious, more- 

 over, and free, and yet at bottom a system of activities, no more. 

 Activity, doing, will, that is the core of us, the rest, sensation, feeling, 

 idea, they are but the effects of our own or of other activities. A spirit, 

 in etymology, is just the active principle of a liquid : and activity is 

 what distinguishes the quick from the dead. Even superman, in his 

 ascending excellence, we must believe to be but vaster and more skill- 

 fully and perfectly ordered activity. And man is distinguished from 

 his humbler brethren, and higher animals from lower, by what they can 

 do. Man hesitates, chooses, plans, contrives and fits things together 

 in fulfilment of his purposes. As we descend the animal scale these 

 activities first diminish, and then disappear, dull routine taking their 

 place. But this implies, not a substitute for activity, merely its sim- 

 plification. And the same decrease of complexity obtains as the transi- 

 tion is made from animals to plants, and from plants to inorganic 

 matter. This no doubt seems a hard saying to those who have not 

 followed discoveries and discussions in this field ; but to those who have 

 it is little more than a commonplace. We do not yet know how inor- 

 ganic activities become systematized into organic, or what determines 

 their form as vegetable or animal. The cell still keeps its secret. But 

 that inorganic is transformed into organic is plainly shown by every 

 breath taken, every meal eaten, and every development of an embryo to 

 maturity, as the reverse transition is shown by all waste processes, 

 including death itself. As men organize themselves into states, and 

 lesser associations, which have organs and modes of activity which no 

 man has, so, it would seem, molecules organize themselves into cells, 

 and cells into living beings, which differ even more in structure and 

 function from the units composing them. 



In substance, then, comparative psychology teaches that a man is a 

 complicated system of activities, sensitive and conscious; an animal a 

 less complicated system, sensitive and conscious; a plant a still less 

 complicated system, sensitive, but only dimly conscious, if at all so; 

 and organic matter, the simplest system of activities we know, whether 

 either sensitive or conscious we are not yet prepared to say. So much 

 is quite plain. But all is not said. It is also plain that inorganic, or 

 so-called dead matter, has, in the way of evolution, developed into 

 organic or living matter, and that matter is being daily transformed 

 into living, yes, into conscious, beings, and living and even conscious 

 beings are being daily transformed back into mere matter. These 

 plain facts of themselves throw not a little light on the nature of 

 matter. For they show that the constitution and the nature of matter 



