It is clear, for one thing, that as simply all and every mental, emotional, and volitional energizing is necessarily and always accompanied by corresponding nerve-states, and that if we had not some neural sensitiveness and neural adaptability, we could not--whilst living our earthly life--think, or feel, or will in regard to anything whatsoever: a certain special degree of at least potential psycho-physical sensitiveness and adaptability must be taken to be, not the productive cause, but a necessary condition for the exercise, of any considerable range and depth of mind and will, and hence of sanctity in general; and that the actual aiming at, and gradual achievement of, sanctity in these, thus merely possible cases, spiritualizes and further defines this sensitiveness, as the instrument, material, and expression of the soul’s work.[38] And this work of the heroic soul will necessarily consist, in great part, in attending to, calling up, and, as far as may be, both fixing and ever renovating certain few great dominant ideas, and in attempting by every means to saturate the imagination with images and figures, historical and symbolic, as so many incarnations of these great verities. We get thus what, taken simply phenomenally and without as yet any inquiry as to an ultimate reality pressing in upon the soul,--a divine stimulation underlying all its sincere and fruitful action,--is a spiritual mono-ideism and auto-suggestion, of a more or less general kind. But, at this stage, these activities and their psycho-physical concomitants and results will, though different in kind, be no more abnormal than is the mono-ideism and auto-suggestion of the mathematician, the tactician, and the constructive statesman. Newton, Napoleon, and Richelieu: they were all dominated by some great central idea, and they all for long years dwelt upon it and worked for it within themselves, till it became alive and aflame in their imaginations and their outward-moving wills, before, yet as the means of, its taking external and visible shape. And, in all the cases that we can test in detail, the psycho-physical accompaniments of all this profound mental-volitional energy were most marked. In the cases of Newton and Napoleon, for instance, a classification of their energizings solely according to their neural accompaniments would force us to class these great discoverers and organizers amongst psycho-physical eccentrics. Yet the truth and value of their work and character has, of course, to be measured, not by this its neural fringe and cost, but by its central spiritual truth and fruitfulness. 2. _Such mechanisms specially marked in Philosophers, Musicians, Poets, and Mystical Religionists._