THE MIND-STUFF THEORY. 151 



sensations from the elementary nerve-tips affected was too 

 small to sum itself distinctly into either of the qualities of 

 feeling in question. He tried to show how a different 

 manner of the summation might give rise in one case to the 

 heat and in another to the touch. 



"A feeling of temperature," he says, "arises when the intensities 

 of the units of feeling are evenly gradated, so that between two 

 elements a and b no other unit can spatially intervene whose intensity 

 is not also between that of a and 6. A feeling of contact perhaps arises 

 when this condition is not fulfilled. Both kinds of feeling, however, are 

 composed of the same units." 



But it is obviously far clearer to interpret such a grada- 

 tion of intensities as a brain-fact than as a mind-fact. If 

 in the brain a tract were first excited in one of the w^ays 

 suggested by Prof. Fick, and then again in the other, it 

 might very well happen, for aught we can say to the con- 

 trary-, that the psychic accompaniment in the one case would 

 be heat, and in the other pain. The pain and the heat would, 

 however, not be comjDosed of psychic units, but would each 

 be the direct result of one total brain-process. So long as 

 this latter interpretation remains open, Fick cannot be held 

 to have proved psychic summation. 



Later, both Spencer and Taine, independently of each 

 other, took up the same line of thought. Mr. Sj^encer's 

 reasoning is worth quoting in extenso. He writes : 



" Although the individual sensations and emotions, real or ideal, of 

 which consciousness is built up, appear to be severally simple, homo- 

 geneous, unanalyzable, or of inscrutable natures, yet they are not so. 

 There is at least one kind of feeling which, as ordinarily experienced, 

 seems elementary, that is demonstrably not elementary. And after re- 

 solving it into its proximate components, we can scarcely help suspect- 

 ing that other apparently-elementary feelings are also compound, and 

 may have proximate components like those which we can in this one 

 instance identify. 



" Musical sound is the name we give to this seemingly simple feeling 

 which is clearly ro^solvable into simpler feelings. "Well known experi- 

 ments prove that when equal blows or taps are made one after another 

 at a rate not exceeding some sixteen per second, the effect of each Is 

 perceived as a separate noise; but when the rapidity with which the 

 blows follow one another exceeds this, the noises are no longer identified 

 in separate states of consciousness, and there arises in place of them a 

 continuous state of consciousness, called a tone. In further increasing 



