This article offers the first systematic investigation of the linguistic forms in which Kant expresses his transcendental idealism since Gerold Prauss’ seminal book Kant und das Problem der Dinge an sich. It is argued that Prauss’ own argument for the claim that ‘in itself’ is an adverbial expression that standardly modifies verbs of philosophical reflection is flawed and that there is hence very poor exegetical evidence for so-called ‘methodological two-aspect’ interpretations of Kant’s transcendental idealism. A comprehensive investigation of Kant’s adverbial (...) uses of ‘in itself’ rather reveals that there are various groups of verbs that ‘in itself’ modifies, which can more or less all be reduced to a standard use in which ‘in itself’ modifies verbs of predicative being such as the copula. It is also discussed how these findings can be accommodated by the two main alternative kinds of interpretations, that is, two-object and ontological two-aspect interpretations. (shrink)

Kant claims that an intuitive understanding—such as God would possess—could cognize things in themselves. This claim has prompted many interpreters of Kant's theoretical philosophy to propose that things in themselves correspond to how an intuitive understanding would cognize things. In contrast, I argue that Kant's theoretical philosophy does not endorse the common proposal that all things in themselves correspond to how an intuitive understanding would cognize things. Instead, Kant's theoretical philosophy maintains that things in themselves might or might not correspond (...) to how an intuitive understanding would cognize things. I then consider whether Kant's moral philosophy and theory of reflecting judgment might provide alternative grounds for claiming that we should regard things in themselves as corresponding to how an intuitive understanding would cognize things. I argue that Kant's moral philosophy does not provide such grounds, but his theory of reflecting judgment does. Thus, interpretations of Kant's transcendental idealism should attend to the differences between Kant's theoretical philosophy, moral philosophy, and theory of reflecting judgment in assessing the relationship between intuitive understanding and things in themselves. (shrink)

While the debate about whether Kant's idealism requires a ‘Two Worlds’ or ‘Two Aspect’ interpretation has reached a seeming impasse, I argue that the account of intelligible possession found in the ‘Doctrine of Right’ provides novel and compelling evidence in favour of an epistemic ‘Two Aspect’ reading of Kant's position.

According to the ‘One Object’ reading of Kant's transcendental idealism, the distinction between the appearance and the thing in itself is not a distinction between two objects, but between two ways of considering one and the same object. On the ‘Metaphysical’ version of the One Object reading, it is a distinction between two kinds of properties possessed by one and the same object. Consequently, the Metaphysical One Object view holds that a given appearance, an empirical object, is numerically identical to (...) the thing in itself that appears as that object. I raise various indiscernibility arguments against that view; because an appearance has different spatiotemporal and modal properties than a thing in itself, no appearance can be identical to a thing in itself. I point out that these arguments are similar to arguments against Monism, the view that material objects are numerically identical to the matter of which they are made. I outline some strategies Monists have developed to respond to these indiscernibility arguments and then develop parallel responses on behalf of the Metaphysical One Object view. However, I then raise another indiscernibility argument, to which, I argue, the Metaphysical One Object view cannot respond, even using the resources I have developed thus far. I develop a modified version of the Metaphysical One Object view that can respond to this new indiscernibility argument, but, I argue, this modified version of the One Object view is only a terminological variant of the Two Object view. When the Metaphysical One Object view is fully thought through it becomes the Two Object view. I conclude that Kantian appearances are not numerically identical to the things in themselves that appear to us. (shrink)

According to the ‘One Object’ reading of Kant's transcendental idealism, the distinction between the appearance and the thing in itself is not a distinction between two objects, but between two ways of considering one and the same object. On the ‘Metaphysical’ version of the One Object reading, it is a distinction between two kinds of properties possessed by one and the same object. Consequently, the Metaphysical One Object view holds that a given appearance, an empirical object, is numerically identical to (...) the thing in itself that appears as that object. I raise various indiscernibility arguments against that view; because an appearance has different spatiotemporal and modal properties than a thing in itself, no appearance can be identical to a thing in itself. I point out that these arguments are similar to arguments against Monism, the view that material objects are numerically identical to the matter of which they are made. I outline some strategies Monists have developed to respond to these indiscernibility arguments and then develop parallel responses on behalf of the Metaphysical One Object view. However, I then raise another indiscernibility argument, to which, I argue, the Metaphysical One Object view cannot respond, even using the resources I have developed thus far. I develop a modified version of the Metaphysical One Object view that can respond to this new indiscernibility argument, but, I argue, this modified version of the One Object view is only a terminological variant of the Two Object view. When the Metaphysical One Object view is fully thought through it becomes the Two Object view. I conclude that Kantian appearances are not numerically identical to the things in themselves that appear to us. (shrink)

In the interpretation of Kant’s transcendental idealism, a textual stalemate between two camps has evolved: two-world interpretations regard things in themselves and appearances as two numerically distinct entities, whereas two-aspect interpretations take this distinction as one between two aspects of the same thing. I try to develop an account which can overcome this dispute. On the one hand, things in themselves are numerically distinct from appearances, but on the other hand, things in themselves can be regarded as they exist in (...) themselves and as they appear. This reveals a mutual entailment of both accounts. Finally, I suggest that this approach most naturally leads to a kind of ‘phenomenalism’, but of a sort not normally attributed to Kant. (shrink)

In The Philosophical Criticism, Alois Riehl developed a realistic interpretation of Kant’s transcendental idealism based on his theory of space and time. In doing so, more than 100 years ago, he formulated an interpretation of the relation between the thing in itself and appearances that is discussed in current research as the metaphysical „dual aspect“ interpretation, although it is rarely attributed to Riehl. To reconstruct Riehl’s position, the research results of comparative studies on Moritz Schlick are systematically extended and applied (...) to the current debate on Kant’s transcendental idealism. (shrink)

Kant’s transcendental idealism hinges on a distinction between appearances and things in themselves. The debate about how to understand this distinction has largely ignored the way that Kant applies this distinction to the self. I argue that this is a mistake, and that Kant’s acceptance of a single, unified self in both his theoretical and practical philosophy causes serious problems for the ‘two-world’ interpretation of his idealism.

We shall address from a conceptual perspective the duality between algebra and geometry in the framework of the refoundation of algebraic geometry associated to Grothendieck’s theory of schemes. To do so, we shall revisit scheme theory from the standpoint provided by the problem of recovering a mathematical structure A from its representations \ into other similar structures B. This vantage point will allow us to analyze the relationship between the algebra-geometry duality and the structure-semiotics duality. Whereas in classical algebraic geometry (...) a certain kind of rings can be recovered by considering their representations with respect to a unique codomain B, Grothendieck’s theory of schemes permits to reconstruct general rings by considering representations with respect to a category of codomains. The strategy to reconstruct the object from its representations remains the same in both frameworks: the elements of the ring A can be realized—by means of what we shall generally call Gelfand transform—as quantities on a topological space that parameterizes the relevant representations of A. As we shall argue, important dualities in different areas of mathematics can be understood as particular cases of this general pattern. In the wake of Majid’s analysis of the Pontryagin duality, we shall propose a Kantian-oriented interpretation of this pattern. We shall use this conceptual framework to argue that Grothendieck’s notion of functor of points can be understood as a “relativization of the a priori” that generalizes the relativization already conveyed by the notion of domain extension to more general variations of the corresponding domains. (shrink)

In the Critique of Pure Reason, Kant draws a distinction between appearances and things in themselves, characterizing the latter as uncognizable. While arguing that all we can cognize are appearances, Kant nevertheless maintains that there are thing in themselves. This has struck many as questionable: how can we be in a position to affirm, of things stipulated to be uncognizable, that they exist? In this paper, I take up the challenge of establishing the existence of things in themselves. I begin (...) by making the case that, given Kant’s epistemological strictures, the existence of things in themselves must follow analytically from the existence of appearances. After examining the pitfalls of a recent attempt at establishing the existence of things in themselves, I go on to argue that the feature of appearances in virtue of which their existence analytically entails the existence of themselves is the subjectivity of their form. It is implicit in the notion of something with a subjective form that its matter is provided via affection from without. Moreover, the things providing the matter of appearances can’t be located in space and time, because appearances themselves depend on our sensibility for their formal features. (shrink)

This is a defense of Kant against the allegedly neglected alternative in his formulation of transcendental idealism. What sets it apart from the contributions of others who have spoken for Kant in this regard is the construction of a general interpretive framework — a reconstruction of the one Kant provides for transcendental idealism — as opposed to the development of an ad hoc defensive strategy for refuting the charges. Hence, comprehensive clarification instead of pointed rebuttal. The difference is between focusing (...) on the text and focusing on the problem. No doubt, doing both is not only possible but also required, as the problem is supposed to be in the text, but the point is that it is not there, and further, that we need not go anywhere else to show that it is not there. Thus, the approach is constructive rather than defensive, or more accurately, constructive as well as defensive. And the construction rests on what Kant actually said rather than on what he might have meant or on what he should have said instead. (shrink)