Charles Peirce's diagrammatic logic — the Existential Graphs — is presented as a tool for illuminating how we know necessity, in answer to Benacerraf's famous challenge that most ‘semantics for mathematics’ do not ‘fit an acceptable epistemology’. It is suggested that necessary reasoning is in essence a recognition that a certain structure has the particular structure that it has. This means that, contra Hume and his contemporary heirs, necessity is observable. One just needs to pay attention, not merely to individual (...) things but to how those things are related in larger structures, certain aspects of which relations force certain other aspects to be a certain way. (shrink)

In his lectures on Logic and Metaphysics, Kant distinguishes between logical and real essences. While the former is related to concepts and is knowable, the latter is related to things and is unknowable. In this paper, I argue that the unknowability is explained by the modal characteristic of real essences as a necessitating ground on which a priori knowledge is impossible. I also show how this claim is related to the unknowable necessity of particular laws of nature. Since laws of (...) nature are conceived as grounded in real essences, the unknowability of the latter is equivalent to Kant's other claim that there can be no knowledge of the necessity of particular laws of nature. Necessity can only be known a priori, and therefore, the necessity of particular laws is only assumed and conceived as grounded in something unknowable, a real essence. This conclusion will allow me to attribute to Kant a position I label as “regulative essentialism”, meaning that real essences have an indispensable role in accordance with the rational interest to explain nature as a system of laws and natural kinds, combined with an epistemic humility about the correspondence of our empirical concepts to real essences. (shrink)

As is well known, the linguistic/philosophical reflection on natural kind terms has undergone a remarkable development in the early seventies with Putnam and Kripke’s essentialist approaches, touching upon different aspects of Kan’s slant. Preliminarily, however, it might be useful to review some of the theoretical stages in Locke and Leibniz’s approaches on natural kind terms in the light of contemporary reflections, to eventually pinpoint Kant’s contribution and see how some commentators have placed it within the theory of direct reference. Starting (...) with textual evidence even from the logical corpus, in the present essay I will attempt to discuss some of the arguments dismissing Kant’s adherence to this view. These assume that in his approach to the semantics of natural kind Kant appears to be still holding on to a nominalist/conceptualist position, though he seems to be well aware of a few key issues for the theorists of direct reference. (shrink)

It is traditionally held that our knowledge of necessity is a priori; but the familiar theories of a priori knowledge – platonism and conventionalism – have now been discredited, and replaced by either modal skepticism or a posteriori essentialism. The main thesis of this paper is that Kant's theory of a priori knowledge, when detached from his transcendental idealism, offers a genuine alternative to these unpalatable options. According to Kant's doctrine, all epistemic necessity is grounded directly or indirectly on our (...) capacity for clear and distinct rational intuition. Insight, in turn, depends upon functions of the imagination for creating “mental models” of necessary truths. This doctrine is well exemplified by Kant's account of our knowledge of simple analytic truths. (shrink)

Consider the laws of nature—the laws of physics, for example. One familiar philosophical question about laws is this: what is it to be a law of nature? More specifically, is a law of nature a regularity, or a generalization stating a regularity? Or is it something else? Another philosophical question is: how, and to what extent, can we have knowledge of the laws of nature? I am interested here in Kant's answers to these questions, and their place within his broader (...) theoretical philosophy during the period spanning from the first to the third Critique. (shrink)

At least Kant thinks it's a part of the concept that gold is to be a yellow metal. He thinks that we know this a priori, and that we could not discover it to be empirically false … Is Kant right about this? Gold [is] … a yellow malleable ductile high density metallic element resistant to chemical reaction. Nature considered materially is the totality of all objects of experience. Kant's joke. Kant wanted to prove in a way that would dumbfound (...) the common man that the common man was right: that was the secret joke of this soul. (shrink)

Recently, Kenneth Westphal has presented a highly interesting and innovative reading of Kant's critical philosophy.2 This reading continues a tradition of Kantscholarship of which, e.g., Paul Guyer's work is representative, and in which the antiidealistic potential of Kant's critical philosophy is pitted against its idealistic selfunderstanding. Much of the work in this tradition leaves matters at observing the tensions this introduces in Kant's work. But Westphal's proposed interpretation goes farther. Its attractiveness derives for the most part from the promise that (...) it permits an internal critique of Kant's transcendental idealism (TI), that is, a critique that is based on the very resources of Kantian transcendental philosophy.3 In contrast to these resources, which currently seem to go through a sort of revival in an enormous array of fields, TI is notorious for dismaying even sympathetic interpreters. How attractive and needed such an internal critique of TI would be becomes all the more patent when we place such a promise in the context of some of the contemporary discussions about TI after Allison's famous defense of it. Before directly engaging with Westphal's interpretation, I would therefore like to quickly sketch on what background it acquires its force (I). After characterizing the main features of Westphal's view (II), and supporting it in more detail by an account of Kant's theory of cognitive significance (III), I then want to review the extent of its success to present Kant as issuing an anti-skeptical argument (IV.1), or semantic views that are incompatible with TI (IV.2), or a 'proof of not merely empirical realism' (IV.3). I agree that purely idealist readings of Kant are mistaken. Westphal's... (shrink)