428 



SCIENCE. 



[N. S. Vol. I. No. 16. 



' by ear ' play by finger-memory ; their 

 memories are muscular or motor. All 

 these memories, then, depend upon the ex- 

 ternal woi'ld. So (3) does imagination. 

 Imagination can put perceptions together 

 in new or unusual ways ; but it can never 

 make a new perception. Try to imagine a 

 color which is different from all the colors 

 that are known. You cannot do it. You 

 may imagine mixtures of colors, hues and 

 tints obtained from combinations of the 

 known colors, which you have never ac- 

 tually seen ; but j'ou cannot imagine a new 

 color. The same fact comes out in works 

 of fiction. When Baron Munchausen takes 

 you to the moon or the dog-star, and shows 

 you their inhabitants ; and when Peter 

 Wilkins describes to you the population of 

 the South Pole — these people are simply 

 human beings, with their characters chang- 

 ed and modified in various ways. They 

 can take their eyes out of their heads and 

 pass them round to their neighbors, or they 

 have wings which fold around them and 

 serve as clothing ; but there is nothing new 

 in all this. It is only the putting of the 

 perceptions together that is new, not the 

 perceptions themselves. And the same is 

 true of all the constructions of the imagina- 

 tion, as thej are called, devils, centaurs, 

 sea-serpents, dragons, hippogriffs, ghosts 

 and the rest of them. 



The world outside of us, then, is respon- 

 sible for a good deal of our mental furni- 

 ture. We can simplify matters, here, for 

 purposes of classification, bj' grouping to- 

 gether sensation, perception, memory-image 

 and imaginary representation, as 'ideas.' 

 Sensation is the raw material fi-om which 

 ideas are built up. As for the other usages: 

 if you cannot remember, you say ' I haven't 

 any idea of what that man's name was ;' 

 and if you are endeavoring to imagine a 

 circumstance, you say ' I haven't any idea 

 of how that could have happened.' 



So much for the first principal category 



of mental experience. Now, in the second 

 place, we are in some respects not at the 

 mercy of the world outside, but the world 

 is at our mercJ^ What is the great difl'er-"" 

 ence between the animal and the plant? 

 Surely this, that the animal can move at 

 will, while the plant is stationary. That 

 seems to be a verj^ simple matter; but just 

 consider how much it means. If the plant 

 is going to lead a stationary life, it can 

 take advantage of the fact — I speak meta- 

 phorically, of course — to be careless of its 

 shape and size; or rather, it must make 

 itself as big and as complicated as it can, 

 in order to secure all the nourishment 

 possible from one settled spot. The result 

 is that the plant carries its lungs and its 

 digestive apparatus all over it, on the out- 

 side. You know the functions of leaves 

 and roots. With the animal the reverse 

 is the case. It is going to move about. It 

 can seek food in different places. The best 

 thing for it, therefore, is to have its lungs 

 and digestive organs packed away inside 

 of it ; so that it can get about with as light 

 a weight to carry, and as convenient a 

 balance of that weight, as possible. There 

 must be no loose ends left on the outside, 

 injury to which would mean inefi&ciency 

 or death. Well ! Yoit see that, by moving 

 among things at its own will and pleasure 

 the animal has a certain power over the 

 external world. How is this power repre- 

 sented in consciousness ? In two principal 

 ways: (1) Whenever we move; or, to put 

 the matter more technicallj'', and more defi- 

 nitely with reference to ourselves as dis- 

 tinct from the lower animals, whenever we 

 act, we have in consciousness the experi- 

 ence of effort, of endeavor. This is an 

 experience quite different fi-om the experi- 

 ence that comes to us as ideas. We can 

 have, naturally, an idea of effort ; that 

 would be the idea of some person making 

 the effort, or the idea of some obstacle to 

 be overcome by effort, or what not. But 



