Page:On the Fourfold Root, and On the Will in Nature.djvu/140

 the necessity with which effect follows cause, with his other assertion that succession in Time is our only empirical criterion for determining which of two states is cause, and which effect. Who does not see the most obvious circle here ?

If we knew objectiveness of succession through Causality, we should never be able to think it otherwise than as Causality, and then it would be nothing else than Causality. For, if it were anything else, it would have other distinctive signs by which to be recognised ; now this is just what Kant denies. Accordingly, if Kant were right, we could not say : "This state is the effect of that one, wherefore it follows it ; "for following and being an effect, would be one and the same thing, and this proposition a tautology. Besides, if we do away with all distinction between following upon and following from, we once more yield the point to Hume, who declared all consequence to be mere sequence and therefore denied that distinction likewise.

Kant's proof would, consequently, be reduced to this : that, empirically, we only know actuality of succession ; but as besides we recognise necessity of succession in certain series of occurrences, and even know before all experience that every possible occurrence must have a fixed place in some one of these series, the reality and the a priority of the causal law follow as a matter of course, the only correct proof of the latter being the one I have given in § 21 of this work.

Parallel with the Kantian theory : that the causal nexus alone renders objective succession and our knowledge of it possible, there runs another : that coexistence and our knowledge of it are only possible through reciprocity. In the "Critique of Pure Reason " they are presented under