474 W. B. BOYCK GIBSON : ises the process of Consciousness. Now this change is by no means a mere Heraclitean flux ; in so far as it is, it has only a subordinate interest for the psychologist. The change which is of primary concern to Psychology is the change known as mental development, a change possessing definite continuity and direction. The fundamental fact within this ceaseless activity of the individual Consciousness is thus, for Psychology, the fact which gives intelligible unity to this activity. The ultimate psychological principle would then seem to be a principle expressive of this unity in a word, the principle of the Unity of Consciousness. What then is this Unity, this fact of the mental life, the presence of which serves to distinguish mental development from mere mental change ? In answer to this question I should like first of all to emphasise this, that what we are in search of is a certain fact required by Psychology as a basis for some theory of mental development. It is thus impera- tive that we should make our own statement as to the scope of Psychology, for the scope determines the data. I propose then, with a view to fixing the fundamental fact, to restrict the scope of Psychology to the study of the development of Consciousness in so far as it is determined, directly or indirectly, by normal attentive processes. A larger concep- tion of the scope of Psychology would of course include subattentive processes and the attentive processes of the multiple Consciousness, but this widening of the scope enor- mously enhances the difficulty of finding as an experiential fact what we have called the Unity of Consciousness. At the same time the restriction should be estimated at its due value, for all actual Consciousness is attentive, attentive Consciousness being by no means synonymous with the reflective Consciousness. In the case of Consciousness that is reflective, Unity of Consciousness is practically the same thing as Consciousness of Unity, but the Unity of Conscious- ness we are considering is a fact that is given with and indeed makes possible not only Consciousness of Unity, whatever that may mean, but the very Consciousness of an object. It is a form of Consciousness that is as characteristic of animals and of savages as it is of civilised adults. Having limited our inquiry in one direction let us now limit it in another. The concept of the Unity of Conscious- ness has had so many meanings given to it that it may be in the interests of clearness to repudiate the more obvious of these as lying outside what we are in search of. In the first place the Unity of Consciousness, as a fundamental fact in mental development is not the simple indestructible
