Schopenhauer’s Transcendental Aesthetic

Schopenhauer’s World as Will and Representation defends an idealism according to which space and time have no reality beyond the world of representation; both are “forms of knowledge, not qualities of the thing in itself.” The locus classicus of such idealism is Kant’s Critique of Pure Reason, a work regarded by Schopenhauer as the most important contribution to philosophy in two thousand years. He claims that Kant’s arguments for idealism, by wholly conquering the innate realism of our original disposition, produce an effect “like that of an operation for cataract on a blind man.” This epiphany is occasioned by the book’s Transcendental Aesthetic chapter, whose proofs have “a complete power of conviction,” and whose propositions “number among the incontestable truths.” Schopenhauer’s praise of Kant here is striking, not least because a broad consensus over two centuries has concluded that the Transcendental Aesthetic’s central argument for its idealist theory of space and time is a clear failure. Schopenhauer’s positive appraisal is usually taken to show that he too simply overlooked the fatal objection to the argument. It is argued that Schopenhauer saw exactly why the classical invalidity objection is mistaken—that he praised Kant’s argument for transcendental idealism because he understood it. His insight leads us to a deeper understanding of one of the pivotal arguments of Kant’s critical philosophy.