Epigenesis of Pure Reason and the Source of Pure Cognitions

Kant describes logic as “the science that exhaustively presents and strictly proves nothing but the formal rules of all thinking”. (Bviii-ix) But what is the source of our cognition of such rules (“logical cognition” for short)? He makes no concerted effort to address this question. It will nonetheless become clear that the question is a philosophically significant one for him, to which he can see three possible answers: those representations are innate, derived from experience, or originally acquired a priori. Although he gives no explicit argument for the third answer, he seems committed to it—especially given his views on the source of pure concepts of the understanding and on the nature of logic. It takes careful preparatory work to gather all the essential materials for motivating and reconstructing Kant’s “original acquisition” account of logical cognition. I shall proceed in two sections. In section 1, I analyze Kant’s argument that pure concepts of the understanding (or intellectual concepts)—as one kind of pure cognition—must be acquired originally and a priori. My analysis partly concerns his varied attitudes toward Crusius’s and Leibniz’s versions of the nativist account of such concepts. I give special attention to how Kant characterizes the nativist account and his own “original acquisition” account in terms of “preformation” and “epigenesis”. My goal is, firstly, to tease out the sense in which Kant grants that there must be an innate ground (or preformation) for the derivation of pure concepts and, secondly, to introduce—and pave the way for answering—the question about the source of logical cognition. In section 2, in light of Kant’s reference to Locke and Leibniz as the greatest reformers of philosophy (including logic) in their times (Log, AA 9: 32), I examine the Lockean and Leibnizian approaches to logic, respectively. Both approaches are “physiological” by Kant’s standard and are directly opposed to his own strictly critical method. I explain how this methodological move shapes Kant’s view that representations of logical rules must be originally acquired a priori. This acquisition involves a kind of radical epigenesis of pure reason: unlike the acquisition of pure concepts, it presupposes no further innate ground (or preformation). This view will have important consequences for issues such as the ground of the normativity of logical rules and the boundaries of their rightful use

Leibniz and the Problem of Temporary Truths

Not unlike many contemporary philosophers, Leibniz admitted the existence of temporary truths, true propositions that have not always been or will not always be true. In contrast with contemporary philosophers, though, Leibniz conceived of truth in terms of analytic containment: on his view, the truth of a predicative sentence consists in the analytic containment of the concept expressed by the predicate in the concept expressed by the subject. Given that analytic relations among concepts are eternal and unchanging, the problem arises of explaining how Leibniz reconciled one commitment with the other: how can truth be temporary, if concept-containment is not? This paper presents a new approach to this problem, based on the idea that a concept can be consistent at one time and inconsistent at another. It is argued that, given a proper understanding of what it is for a concept to be consistent, this idea is not as problematic as it may seem at first, and is in fact implied by Leibniz’s general views about propositions, in conjunction with the thesis that some propositions are only temporarily true

Multiple actualities and ontically vague identity

Gareth Evans's argument against ontically vague identity has been picked over on many occasions. But extant proposals for blocking the argument do not meet well-motivated general constraints on a successful solution. Moreover, the pivotal position that defending ontically vague identity occupies vis a vis ontic vagueness more generally has not yet been fully appreciated. This paper advocates a way of resisting the Evans argument meeting all the mentioned constraints: if we can find referential indeterminacy in virtue of ontic vagueness, we can get out of the Evans argument while still preserving genuinely ontically vague identity. To show how this approach can vindicate particular cases of ontically vague identity, I develop a framework for describing ontic vagueness in general in terms of multiple actualities. The effect, overall, is to provide a principled and attractive approach to ontically vague identity that is immune from Evansian worries

Leibniz's Metaphysical Logic

Paper by Baruch Brod

Leibniz's Infinitesimals: Their Fictionality, Their Modern Implementations, And Their Foes From Berkeley To Russell And Beyond

Many historians of the calculus deny significant continuity between infinitesimal calculus of the 17th century and 20th century developments such as Robinson's theory. Robinson's hyperreals, while providing a consistent theory of infinitesimals, require the resources of modern logic; thus many commentators are comfortable denying a historical continuity. A notable exception is Robinson himself, whose identification with the Leibnizian tradition inspired Lakatos, Laugwitz, and others to consider the history of the infinitesimal in a more favorable light. Inspite of his Leibnizian sympathies, Robinson regards Berkeley's criticisms of the infinitesimal calculus as aptly demonstrating the inconsistency of reasoning with historical infinitesimal magnitudes. We argue that Robinson, among others, overestimates the force of Berkeley's criticisms, by underestimating the mathematical and philosophical resources available to Leibniz. Leibniz's infinitesimals are fictions, not logical fictions, as Ishiguro proposed, but rather pure fictions, like imaginaries, which are not eliminable by some syncategorematic paraphrase. We argue that Leibniz's defense of infinitesimals is more firmly grounded than Berkeley's criticism thereof. We show, moreover, that Leibniz's system for differential calculus was free of logical fallacies. Our argument strengthens the conception of modern infinitesimals as a development of Leibniz's strategy of relating inassignable to assignable quantities by means of his transcendental law of homogeneity.Comment: 69 pages, 3 figure

From Logical Calculus to Logical Formality—What Kant Did with Euler’s Circles

John Venn has the “uneasy suspicion” that the stagnation in mathematical logic between J. H. Lambert and George Boole was due to Kant’s “disastrous effect on logical method,” namely the “strictest preservation [of logic] from mathematical encroachment.” Kant’s actual position is more nuanced, however. In this chapter, I tease out the nuances by examining his use of Leonhard Euler’s circles and comparing it with Euler’s own use. I do so in light of the developments in logical calculus from G. W. Leibniz to Lambert and Gottfried Ploucquet. While Kant is evidently open to using mathematical tools in logic, his main concern is to clarify what mathematical tools can be used to achieve. For without such clarification, all efforts at introducing mathematical tools into logic would be blind if not complete waste of time. In the end, Kant would stress, the means provided by formal logic at best help us to express and order what we already know in some sense. No matter how much mathematical notations may enhance the precision of this function of formal logic, it does not change the fact that no truths can, strictly speaking, be revealed or established by means of those notations

The Logic of Opacity

We explore the view that Frege's puzzle is a source of straightforward counterexamples to Leibniz's law. Taking this seriously requires us to revise the classical logic of quantifiers and identity; we work out the options, in the context of higher-order logic. The logics we arrive at provide the resources for a straightforward semantics of attitude reports that is consistent with the Millian thesis that the meaning of a name is just the thing it stands for. We provide models to show that some of these logics are non-degenerate

LEIBNIZ\u2019S MIRROR THESIS. SOLIPSISM, PRIVATE PERSPECTIVES AND CONCEPTUAL HOLISM

One of the symbolic images to which Leibniz constantly entrusted the synthesis of his philosophy regards the idea of considering one and the same city from various visual perspectives. Such an image is diffused throughout all Leibniz\u2019s writings and clearly reflects the philosopher\u2019s interest for matters regarding perspective as well as optical phenomena. The point of view of its inhabitants can therefore be compared to a mirror that reflects some different portions of reality. But what do the city-viewers really see? Do they all see exactly the same thing? And assuming the plurality of points of view, how one can be sure that they share the same representative content? The paper presented here tries to offer a plausible interpretation of this topic also by linking different and somehow remote Leibnizian doctrines together

Infinite vs. Singularity. Between Leibniz and Hegel

The aim of this paper is to reconsider the controversial problem of the relationship between the philosophy of Hegel and Leibniz. Beyond the thick curtain of historical references (which have been widely developed by scholars), it is in fact possible to assume some guideline concepts (i.e. those of \u2018singularity\u2019 and \u2018infinity\u2019) to reconstruct the deep theoretical influence which Leibniz played in Hegel\u2019s thought since the Jenaer Systementwurf of 1804/05