16 THE WORLD AS IDEA.
character — can only be deduced from the dependence of all experience upon it; and this deduction can only be accomplished by proving, in the manner here indicated, and explained in the passages referred to above, that the knowledge of causality is included in perception in general, to which all experience belongs, and therefore in respect of experience is completely a priori, does not presuppose it, but is presupposed by it as a condition. This, however, cannot be deduced in the manner attempted by Kant, which I have criticised in the essay on "The Principle of Sufficient Reason," § 23.
§ 5. It is needful to guard against the grave error of supposing that because perception arises through the knowledge of causality, the relation of subject and object is that of cause and effect. For this relation subsists only between the immediate object and objects known indirectly, thus always between objects alone. It is this false supposition that has given rise to the foolish controversy about the reality of the outer world; a controversy in which dogmatism and scepticism oppose each other, and the former appears, now as realism, now as idealism. Realism treats the object as cause, and the subject as its effect. The idealism of Fichte reduces the object to the effect of the subject. Since however, and this cannot be too much emphasised, there is absolutely no relation according to the principle of sufficient reason between subject and object, neither of these views could be proved, and therefore scepticism attacked them both with success. Now, just as the law of causality precedes perception and experience as their condition, and therefore cannot (as Hume thought) be derived from them, so object and subject precede all knowledge, and hence the principle of sufficient reason in general, as its first condition; for this principle is merely the form of all objects, the whole nature and possibility of their existence as phenomena: but the object always presupposes the subject; and therefore between these two
