From the fact that my concept of the unconditioned synthetic unity of the series is always self-contradictory, I conclude there really is a unity of the opposite kind although I have no concept of it. Follows the analogy of the hypothetical syllogism. Falls into contradictions, both sides of which seem to be true. Because they concern only the synthesis of appearances, therefore only empirical.
Reason frees the concept from the limits of empirical experience.
It does this by carrying the empirical synthesis as far as the unconditioned according to the principle that if the conditioned is given, the entire sum of conditions, and consequently the absolutely unconditioned is also given. The transcendental ideas are therefore categories extended to the unconditioned. Time is, in itself, a series and is the formal condition of all series. We will only be concerned with past time which is necessarily thought as being given in its entirety. Space in itself does not constitute a series.