Now, experience is essentially dynamic, and, for an organism, to be active is to be functionally ordinated or focalized. For example, the eye and other parts may be subservient, in different ways and degrees, to the hand. Then the organism is focalized into an organ of touch, of striking, or whatever it may be. Every other function contributes as accessory to this primary function, in the organism’s present phase. We have called consciousness the formal aspect of activity, and we mean by “form” applied to activity what we mean elsewhere, determinateness or definableness. Here, in particular, it is that character which depends on resistance or reactivity. Activity without resistance would be without determination; its character or content would have vanished; it would be activity upon nothing, which, like consciousness of nothing, is nothing. So the resistance that factors in activity is not extraneous to the essence of activity, and consciousness and material processes imply each other not only with the same logical necessity but with the same polar oppositeness of mutual relation, as the aspects of relief. Consciousness is thus the inversion or reciprocal aspect of organic activity, virtual, in distinction from externalized or real, activity. Where attention is focalized, action is most resisted. As action approaches free vent, consciousness of the object of this free activity becomes more and more evanescent. At the limit where action is unresisted, it and consciousness go out, vanish together, in inverse “sense” or directions. Where action approaches “pure” (_i. e._, unresisted) activity, pure positivity, pure subjectivity, consciousness approaches “pure” (_i. e._, unreacting) passivity, pure negativity, pure objectivity. And such “pure” action and consciousness are pure nothing, action on nothing, sensation of nothing. The vanishing of the two relations together is, in each case, for lack of one of its terms inverse to the term lacking in the other case. This mutual symmetry between action and consciousness is an implicate of their identity of denotation and mutual inversion of aspect; and any study of the fluctuations and transitions of consciousness, with its modulations of attention and inhibition, is accordingly a study in inverse, a perfect logical function, of corresponding modifications of organic activity; for in the play of the organic functions we shall find incessant modulations between their focalization and their dispersion, incessant shifting of their mutual rank and of the position of primacy among them, to correspond with the changes between margin and focus that are always going on among the elements of consciousness.