The World as Will and Idea, Vol. I — Arthur Schopenhauer, trans. Haldane & Kemp

THE WORLD AS IDEA.

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arrives at perceptions ; how this alone affords the solution of so many phenomena of the senses ; the si^k^ vision of two eyes, th^ dmible yision^in the case of a squint, or \vhen we try to look at . ppcQ wTiicli lie atjunequal distances behind each oth^5.; and all illusion which is produced by a sudden alteration in the organs of sense. But I have treated this important subject much more fully and thoroughly in the second edition of the essay on “ The Principle of Sufficient Eea^qn^” § 2 1. '''^TT^tliat is said there would find its proper jdace here, and would thcr(.‘fore have to be said again; but as I have almost as much disinclination to quote myself as to quote others, and as I am unable to explain the subject better than it is explained there, I refer the reader to it, instead of quoting it, and take for granted that it is known.

The process by which children, and persons born blind who have been operated upon, learn to see, the single vision of the double sensation of two eyes, the double vision and double touch which occur when the organs of sense have been displaced from their usual position, the upright appearance of objects while the picture on the retina is upside down, the attributing of colour to the outward objects, whereas it is merely an inner function, a division Jhrougji polarisation, of_ the activity of the eye, and lastly the stereoscope, — all these are sure and incontrovertible evidence that perception is not merely of the senses, but intellectual— that is, pure knowledge through the understanding of the cmiM from the effect, and that, consequently, it presupposes the law of causality, in a knowledge of which all perception — that is to say all experience, by virtue of its primary and only possibility, depends. The contrary doctrine that the law of causality results from experience, which was the scepticism of Hume, is first refuted by this. For the independence of the knowledge of causality of all experience, — that is, its a priori i6 THE WORLD 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 Keason,” § 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 coniroversy 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. Kealism treats the object as cause, and the si^ject as its effect The idealism of Fichte reduces the object to the effect of the subject. Since however, and xhis 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 presuDDOses the subject: and therefore between these two

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