essence. But I have yet to find a student who, with growing power of introspection, did not report that to him such sensations seemed to constitute the 'feel' of effort. Moreover, the cumulative force of such statements is very great, if not logically conclusive. Many state that if they relax their muscles entirely it is impossible to keep up the effort. Sensations frequently mentioned are those connected with breathing,—stopping the respiration, breathing more rapidly, contracted chest and throat; others are contraction of brow, holding head fixed, or twisting it, compression of lips, clenching of fist, contraction of jaws, sensations in pit of stomach, goneness in legs, shoulders higher, head lower than usual, fogginess or mistiness in visual field, trying to see something which eludes vision, etc.
But upon the whole I intend rather to assume that the sense of effort is, in all its forms, sensationally conditioned. We have in this fact (if it be a fact) no adequate psychology of effort, but only the preliminary of such theory. The conception up to this point has, for theoretical purposes, negative value only; it is useful in overthrowing other theories of effort, but throws no positive light upon its nature. The problem of interest, as soon as the rival theories are dismissed, comes to be this: Granted the sensational character of the consciousness of effort, what is its specific differentia? What we wish now to know is what set of sensory values marks off experiences of effort from those closely resembling, but not felt as cases of effort. So far as I know this question has not been raised.
How then does, say, a case of perception with effort differ from a case of 'easy' or effortless perception? The difference, I repeat, shall be wholly in sensory quale; but in what sensory quale?
At this point a reversion to a different point of view, and the introduction of a different order of ideas is likely to occur. We may be told, as an explanation of the difference, that in one case we have a feeling of activity, a feeling of the putting forth of energy. I found that persons who in special cases have become thoroughly convinced of the sensational quality of all consciousness of effort, will make this answer. The
