series of the conditions of a conditioned; not, consequently, when the question relates to the descending series of consequences, or to the aggregate of the co-ordinated conditions of these consequences. For, in relation to a given conditioned, conditions are presupposed and considered to be given along with it. On the other hand, as the consequences do not render possible their conditions, but rather presuppose them—in the consideration of the procession of consequences (or in the descent from the given condition to the conditioned), we may be quite unconcerned whether the series ceases or not; and their totality is not a necessary demand of reason. Thus we cogitate—and necessarily—a given time completely elapsed up to a given moment, although that time is not determinable by us. But as regards time future, which is not the condition of arriving at the present, in order to conceive it; it is quite indifferent whether we consider future time as ceasing at some point, or as prolonging itself to infinity. Take, for example, the series m, n, o, in which n is given as conditioned in relation to m, but at the same time as the condition of o, and let the series proceed upwards from the conditioned n to m (l, k, i, etc.), and also downwards from the condition n to the conditioned o (p, q, r, etc.)—I must presuppose the former series, to be able to consider n as given, and n is according to reason (the totality of conditions) possible only by means of that series. But its possibility does not rest on the following series o, p, q, r, which for this reason cannot be regarded as given, but only as capable of being given (dabilis). I shall term the synthesis of the series on the side of the conditions—from that nearest to the given phenomenon up to the more remote—regressive; that which proceeds on the side of the conditioned, from the immediate consequence to the more remote, I shall call the progressive synthesis. The former proceeds in antecedentia, the latter in consequentia. The cosmological ideas are therefore occupied with the totality of the regressive synthesis, and proceed in antecedentia, not in consequentia. When the latter takes place, it is an arbitrary and not a necessary problem of pure reason; for we require, for the complete understanding of what is given in a phenomenon, not the consequences which succeed, but the grounds or principles which precede.