How this act of op-positing is possible and necessary, only becomes clear in the practical philosophy, and even there the inherent difficulty leads to a higher view.
But in consciousness there is equally given a primitive act of op-positing, or contra-positing, formally distinct from the act of position, but materially determined, in so far as what is op-posited must be the negative of that which was posited.
If the ego be pure activity, free activity, it can only become aware of itself by positing some limit.
This construction, or self-determination, is what Fichte called positing (setzen).
Hence he united theoretical and practical reason, which Kant had separated, and both with will, which Kant had distinguished; for he held that the Ego, in positing the non-Ego, posits both its own limit and its own means to the end, duty, by its activity of thinking which requires will.
In philosophy he found the basis for positing a, collective human will, revealing in its activities the materials for determining ethical laws.
The pure ego is inferred from the fact that the non-ego is realized only in the act of the ego in positing it.
(I) This must exclude everything negative; for non-A sublates instead of positing, and is not absolute, but relative to A.