In the common acceptation of the causal relation the cause is finite, to such extent as its content is so (as is also the case with finite substance), and so far as cause and effect are conceived as two several independent existences; which they are, however, only when we leave the causal relation out of sight. In the finite sphere we never get over the difference of the form-characteristics in their relation: and hence we turn the matter round and define the cause also as something dependent or as an effect. This again has another cause, and thus there grows up a progress from effects to causes _ad infinitum._ There is a descending progress too: the effect, looked at in its identity with the cause, is itself defined as a cause, and at the same time as another cause, which again has other effects, and so on for ever. The way understanding bristles up against the idea of substance is equalled by its readiness to use the relation of cause and effect. Whenever it is proposed to view any sum of fact as necessary, it is especially the relation of causality to which the reflective understanding makes a point of tracing it back. Now, although this relation does undoubtedly belong to necessity, it forms only one aspect in the process of that category. That process equally requires the suspension of the mediation involved in causality and the exhibition of it as simple self-relation. If we stick to causality as such, we have it not in its truth. Such a causality is merely finite, and its finitude lies in retaining the distinction between cause and effect unassimilated. But these two terms, if they are distinct, are also identical. Even in ordinary consciousness that identity may be found. We say that a cause is a cause, only when it has an effect, and _vice versâ._ Both cause and effect are thus one and the same content: and the distinction between them is primarily only that the one lays down, and the other is laid down. This formal difference however again suspends itself, because the cause is not only a cause of something else, but also a cause of itself; while the effect is not only an effect of something else, but also an effect of itself. The finitude of things consists accordingly in this. While cause and effect are in their notion identical, the two forms present themselves severed so that, though the cause is also an effect, and the effect also a cause, the cause is not an effect in the same connexion as it is a cause, nor the effect a cause in the same connexion as it is an effect. This again gives the infinite progress, in the shape of an endless series of causes, which shows itself at the same time as an endless series of effects.