condition of the possibility of categories in general. Therefore, the ego does not itself belong among the root concepts of the understanding, as Kant calls the categories; instead, as Kant expresses it, the ego is "the vehicle of all concepts of the understanding." It first of all makes possible the basic a priori ontological concepts. For the ego is not something isolated, not a mere point, but always "I-think," that is, "I-combine." And Kant interprets the categories as that which, in every combining by the understanding, has already been seen and understood beforehand as what provides the corresponding unity of the combined for each combining to be accomplished. The categories are the possible forms of unity of the possible modes of the thinking "I-combine." Combinability and, corresponding to it, its own form, its respective unity, are grounded in the "I-combine." Thus the ego is the fundamental ontological condition, the transcendental that lies at the basis of every particular a priori. We now understand that the ego as the I-think is the formal structure of personality as personalitas transcendentalis.
β) Personalitas psychologica
This, however, does not exhaustively define the concept of subjectivity in Kant. To be sure, this concept of the transcendental ego remains the model for the further interpretation of egohood, personality in the formal sense. But personalitas transcendentalis does not coincide with the complete concept of personality. From the personalitas transcendentalis, the ontological concept of egohood in general, Kant distinguishes the personalitas psychologica. By this he means the factual faculty, grounded in the personalitas transcendentalis, in the "I think," to become conscious of its empirical states, of its representations as occurrences that exist and are always varying. Kant makes a distinction between pure self-consciousness and empirical self-consciousness or, as he also puts it, between the ego of apperception and the ego of apprehension. Apprehension means perception, the experience of the extant, namely, the experience of extant psychical processes by means of the so-called inner sense. The pure ego, the ego of self-consciousness, of transcendental apperception, is not a fact of experience; in all empirical experiencing, 1 am already conscious of this ego as "I experience," the ontological ground of the possibility of all experiencing. The empirical ego as soul can likewise be thought theoretically as an idea and then it coincides with the concept of soul, where soul is conceived as the ground of animality or, as Kant says, of animateness, of life in general. The ego as personalitas transcendentalis is the ego that is essentially always only subject, the subject-ego. The ego as personalitas psychologica is the ego that is always only an object, something encountered as extant, the object-ego, or as Kant