For since in the first case the cognition (the conclusio) is given only as conditioned, we cannot reach it by means of reason except at least on the presupposition that all members of the series are given on the side of the conditions (totality in the series of premises), because only under this presupposition is the judgment before us possible a priori; on the contrary, on the side of that which is conditioned or of the consequences, there is thought only a series that becomes, and that is not already presupposed or given as a whole, and so only a potential progression.