Robert Watt

abstract: It is generally agreed that what Kant means by quid juris in the first sentence of the Deduction of the Pure Concepts of the Understanding is the question whether the claim at hand is legally valid, and that what he means by quid facti is a “neutral foil” to quid juris. I defend an alternative interpretation, according to which quid juris is the question whether certain facts are sufficient for the legal validity of the claim at hand, and quid facti is the question: what are the facts? This interpretation is supported by the way that the terms quaestio juris and quaestio facti were used in the Roman-German legal tradition. It is also supported by Kant’s claim that “jurists... demand proof of both,” and by the structure of the legal deductions in Kant’s own writings. Finally, it sheds light on the aim and structure of the Deduction itself.

Many philosophers have been puzzled by Kant's decision to insert the Refutation of Idealism into the second edition of the first Critique at the end of his elucidation of the Second Postulate. This article proposes a solution to the puzzle. It defends an explanation for the location of Kant's Refutation of Idealism that is plausibly expressed by Kant's claim at the end of his elucidation of the Second Postulate that the Refutation of Idealism is ‘here in its right place’ because ‘[a] powerful objection against these rules for proving existence indirectly is made by idealism’. According to this explanation, the Refutation of Idealism is Kant's response to the objection that the Second Postulate must be false since otherwise idealism is true. This article also considers and rejects a number of alternative explanations for the location of Kant's Refutation of Idealism.

The subject of this article is a powerful objection to the non-conceptualist interpretation of Kant’s transcendental deduction of the categories. Part of the purpose of the deduction is to refute the sort of scepticism according to which there are no objects of empirical intuition that instantiate the categories. But if the non-conceptualist interpretation is correct, it does not follow from what Kant is arguing in the transcendental deduction that this sort of scepticism is false. This article explains and assesses a number of possible responses to this objection.