It would seem highly desirable, in order to keep clear the distinction between intensity and feeling-of-intensity, to restrict the term Excitement to the latter meaning, and substitute the general term Intensity for all objective excitement so-called. It is also greatly to be desired that the reflex states which arise from sudden or great changes in quality, quantity and intensity of consciousness, and which are commonly termed feelings, should receive more general attention from psychologists than heretofore. I have in this paper essayed something in this direction, but it is a very large field, and comparatively unexplored.
However, so far as the problem of feeling as indifference is concerned, enough has been said on Excitement and Intensity, and I shall now consider Neutralisation as giving neutral feeling, a method suggested by Mr. Johnson (_Mind_, xiii. 82), and developed by Miss Mason (xiii. 253). Does a feeling, neutral as regards pleasure and pain, result from the union in one consciousness of a pleasure and pain of equal intensities? Is there a composition of equal pleasure-pain forces so that resultant equals zero? Such a question implies a clear apprehension of what is meant by being in consciousness, and as to the possibility of perfect coincidence and equality in mental activities. It is plain that so far as consciousness is linear, neutralisation cannot occur. Where there is but one track, and but one train at a time, collision is impossible. Mental states often appear coexistent while they are really consecutive. It is doubtful whether pain from toothache and pleasure from music ever appear in absolute synchronism in consciousness, but they may alternate so rapidly sometimes as to appear synchronous to uncritical analysis. To a man drowning, a lifetime of conscious experience seems condensed into a few seconds. This means a consciousness made very sensitive and very rapid in its movement, and which acts like a camera taking pictures with a lightning-shutter. Even if a pleasure and pain did coincide, it is probable that in no case would they be exactly equal. In mental life as in organic life every product has an individuality: as every leaf differs from every other leaf, so every mental state is on completest observation _sui generis_. This is evidently a most delicate investigation, but I doubt whether it can ever be shown that two equal pleasures and pains ever appear in the same sense in consciousness at the same time. Practically equal pleasures and pains in consecutive consciousness lead to vacillation, and the secondary pain of alternation and excitement drives intelligent agents to new activity, or in stupid agents the alternation may be carried to exhaustion.