Phenomenology of Spirit, Preface, paragraph 17

In my view – a view which must be justified only by the exposition of the system itself – everything depends on grasping and expressing the true not as substance but just as much as subject. At the same time we must note that substantiality comprises the universal or the immediacy of knowledge itself, as well as that which is being or immediacy for knowledge. If the age which heard God spoken of as the one substance was shocked and revolted by such a characterisation of His nature, partly it was due to the instinctive feeling that in such a conception self-consciousness was simply submerged and not preserved, but partly the opposite position, which adheres to thinking as thinking, universality as such, is the same simplicity or undifferentiated, unmoved substantiality. And even if, in the third place, thought combines with itself the being of substance, and conceives immediacy or contemplation as thinking, it still depends upon whether this intellectual contemplation does not fall back into that inert simplicity and expound reality itself in an unreal manner.