§ 380. The "concrete" nature of mind involves for the observer the peculiar difficulty that the several grades and special types which develop its intelligible unity in detail are not left standing as so many separate existences confronting its more advanced aspects. It is otherwise in external nature. There, matter and movement, for example, have a manifestation all their own--it is the solar system; and similarly the _differentiae_ of sense-perception have a sort of earlier existence in the properties of _bodies_, and still more independently in the four elements. The species and grades of mental evolution, on the contrary, lose their separate existence and become factors, states and features in the higher grades of development. As a consequence of this, a lower and more abstract aspect of mind betrays the presence in it, even to experience, of a higher grade. Under the guise of sensation, e.g., we may find the very highest mental life as its modification or its embodiment. And so sensation, which is but a mere form and vehicle, may to the superficial glance seem to be the proper seat and, as it were, the source of those moral and religious principles with which it is charged; and the moral and religious principles thus modified may seem to call for treatment as species of sensation. But at the same time, when lower grades of mental life are under examination, it becomes necessary, if we desire to point to actual cases of them in experience, to direct attention to more advanced grades for which they are mere forms. In this way subjects will be treated of by anticipation which properly belong to later stages of development (e.g. in dealing with natural awaking from sleep we speak by anticipation of consciousness, or in dealing with mental derangement we must speak of intellect).
§ 381. From our point of view Mind has for its _presupposition_ Nature, of which it is the truth, and for that reason its _absolute prius_. In this its truth Nature is vanished, and mind has resulted as the "Idea" entered on possession of itself. Here the subject and object of the Idea are one--either is the intelligent unity, the notion. This identity is _absolute negativity_--for whereas in Nature the intelligent unity has its objectivity perfect but externalised, this self-externalisation has been nullified and the unity in that way been made one and the same with itself. Thus at the same time it is this identity only so far as it is a return out of nature.