The philosophy in this domain (=epistemology) attempts to investigate and grasp objective reality by means of pure self consciousness. Within self consciousness, the ideal power is in opposition to the real power. The ideas of reality give rise to the fact that these two powers determine each other in gradation, i.e., step by step. This theoretical philosophy pursues the development of Spirit or Subjectivity. The development of Spirit reveals itself in the process in which Spirit, being first in the limitations and confinements at the beginning, gradually liberates itself as a freer concept and ultimately discovers itself in absolute freedom as the activity of Will. In this, theoretical intellect turns into practical intellect.
This process of Spirit’s development may be divided into three epochs:
The 1st epoch
This is the process in which Spirit from primary sensation becomes productive intuition. In sensation (Empfindung), Spirit finds itself as highly restricted. Here Self restricts itself as the condition for consciousness: While the activity of self restriction does not come into and remains outside of consciousness itself, such self-restriction is found as restriction without the activity of Self itself. In productive intuition, the sensed and the act of sensing are distinguished, namely the thing in itself (Ding an sich) and I in itself (Ich an sich). Here I or Ego productively intuits its own real activities and ideal activities. Because the I in itself and the thing in itself can neither separate from nor co-exist with each other, the phenomenon (Erscheinung) arises as their medium.
The 2nd epoch
The process of Spirit from productive intuition to reflection. This is the process in which the I that has become productive intuition reflects itself as such. When the I reflectively grasps itself in its activity, it is Time. In other words, Time is for I to act, while at the same time, the sensory object appears as the negation of Time, i.e., as Space. When Time and Space are related to objectivity, the object appears as Substance by its spaciality and the object appears as an Accident in temporality. Therefore, we philosophers began to distinguish within I Space and Time, within objectivity Substance and Accident. From the above, Time and Space as forms of intuition are to be explained, while the category of Substance is deduced. Further, the category of Causality and that of Mutual Determination (Wechselwirkung) are to be deduced.
The 3rd epoch
The operation in which Spirit becomes from reflection the Absolute Will. The first step is accomplished by the fact that I make a judgment. To judge is first to separate intuition and concept by abstraction and then to unify them as the subject and the predicate. The final step will be the activity of will, which is the completion of productive intuition. While productive intuition is unconscious production, will is conscious production. By voluntary action, the world becomes objective, and by mutual interaction with other Selves, Self attains the consciousness of the real external world and the freedom of itself.