“In every cognition of an object there is, namely, unity of the concept, which one can call qualitative unity insofar as by that only the unity of the comprehension (Zusammenfassung) of the manifold of cognition is thought, as, say, the unity of the theme in a play, a speech, or a fable.“

— Kant, Critique of Pure Reason (1787), B114




A Pluralistic Account of Reason in Kant’s Philosophy of Science

Thomas Sturm

(ICREA, Barcelona / Autonomous University of Barcelona / Immanuel Kant Baltic Federal University, Kaliningrad)

Some scholars ascribe to Kant an account of what “scientific rationality” is, but their interpretations are one-sided or overly selective. A comprehensive study of his views reveals that reason fulfils a number of quite different functions for the sciences. I first discuss interpretations such as those of Michael Friedman, Margaret Morrison, and Thomas Wartenberg. I show how beyond transcendental and regulative functions, reason makes possible experimentation, places constraints on explanatory reasoning with hypotheses, guides the organization of the system of all sciences, determines aims of science, and is also a theoretical concept for some special sciences. These functions are irreducibly distinct. Seen in this light, reason seems to be a less unified faculty; it seems to be organized in modules, just like sensibility is. Finally, I clarify how my interpretation allows to view these functions are irreducibly distinct but systematically related nonetheless.


Kant’s Transcendental Logic Presupposes That Ideas of Reason are Totalities

Michiel van Lambalgen

(University of Amsterdam)

Kant’s logic resembles modern mathematical logic in that it is concerned with possibly infinite collections of judgements, not just the small sets of premises occurring in the standard inferences of reason (syllogisms etc).  The infinite sets considered in the Jäsche Logik and the Transcendental Analytic are harmless because they arise as the set of consequences of a given judgement.  Kant’s logical version of the Principle of Sufficient Reason, as stated explicitly in the Jäsche Logik, is of this form. In the Tr. An. (B114-6), possibly infinite sets of judgements are brought under the Categories of Quantity, ensuring that such sets have a finite description. We will explain how the logical principles obtained in this way are foundational in modern logic. In the Transcendental Dialectic, Reason is said to exhort us to extend theories indefinitely by a regressus. Kant argues that we cannot have any concept of this  transcendental Idea, which thus cannot be synthesised into a totality  It will be shown that such a totality, i.e. the constitutive use of ideas of Reason, is necessary for the (self-)cognition of transcendental logic and, arguably, also of general logic.


The End of Explanation: Kant and the Domain of Science

James Hebbeler

(Saint Joseph’s University)

 In the Metaphysical Foundations of Natural Science Kant sets out the requirement for proper science that it contain “a priori” and “apodictic” cognition of its laws.  In the first part of the paper, I will present a reading of Kant according to which the fundamental goal of proper science, from which these features flow, is a particular notion of explanation.  In the second part of the paper, I will argue that this very property of proper science, which itself is quite demanding, also has a consequence that makes Kant’s overall view much less demanding than standardly assumed: namely, that the domain of proper science is rather clearly demarcated from its metaphysical foundations.  Where explanation in Kant’s sense ends, so does science.  We should thus reject the idea that proper science needs metaphysical knowledge for its own purposes, and distinguish between two different needs, and thus projects, of reason: the scientific and the philosophical.


Kant on Scientific Hypotheses: Historical and Systematic Perspectives

Hein van den Berg (University of Amsterdam)
Boris Demarest (Heidelberg University)

This paper provides an historical and systematic investigation of the role of hypotheses and explanation based on hypotheses in Kant’s philosophy of science. In the first part of the paper, we provide an historical overview of conceptions of hypotheses in 18th century German philosophy of science, considering the works of Wolff, Meier, Crusius, and Kant. We sketch different conceptions of hypotheses and elucidate the different theories of probability informing these conceptions. In the second part of the paper, we adopt a systematic perspective and argue that contemporary accounts of what a good scientific hypothesis is resemble Kant’s account of scientific hypotheses. We defend Kant’s idea that scientific hypotheses must articulate real possibilities and we consider the role of simplicity and empirical adequacy in explanations based on hypotheses.


Kant’s Theory of Testimony and Its Use in Natural Science

With a Case Study of his Treatment of Travel Reports

Huaping Lu-Adler

(Georgetown University)

A testimony is somebody else’s reported experience of what has happened. It is an indispensable source of knowledge. It only gives us historical cognition, however, which stands in a complex relation to rational or philosophical cognition: while the latter presupposes historical cognition as its matter, one needs the architectonic “eye of a philosopher” to select, interpret, and organize historical cognition. Kant develops this rationalist theory of testimony in his logic lectures. He also practices it in his writings on natural science, including his two essays on race from the 1780s. In these essays, he insists on treating race from the standpoint of a natural philosopher (Naturforscher), who (as Kant puts it in the first Critique) learns from nature “like an appointed judge who compels witnesses to answer the questions he puts to them.” This view underwrites Kant’s use of travel reports (a type of testimony) in developing his natural-scientific account of race, a use that in turn problematizes his rationalist approach to testimony.


Between Old and New Teleology.

Kant on Maupertuis’ Principle of Least Action

Rudolf Meer

(Immanuel Kant Baltic Federal University, Kaliningrad / University of Graz)

In the Appendix to the Transcendental Dialectic, Kant formulates teleological principles or rather ideas and explicates them referring to concrete examples of natural science, such as chemistry, astronomy, biology, empirical psychology, and physical geography. Kant’s decisive point of reference, although not mentioned by name, is Pierre Louis Moreau de Maupertuis and his principle of least action. In 1781, Kant transformed teleology into heuristics and methodology, but in doing so he partially develops a teleology which was disqualified by Maupertuis because its starting point lies in the construction of animals or plants, the structure of the earth and the immensity of the celestial bodies. Based on Maupertuis’ principle of action, it can be shown that the Appendix forms a systematic interface between Universal Natural History and Theory of the Heavens and Critique of Judgement which allows to reconstruct Kant’s teleological considerations in the context of natural science and his critical appraisal of Maupertuis.


Kant’s Normative Conception of Science

Angela Breitenbach

(King’s College, University of Cambridge)

Kant is well-known for his remarkably strict conception of science. “Proper science”, as he calls it, is any body of cognition that is systematically unified, ordered by rational principles, and known with apodictic certainty. Kant is also deeply interested in a large variety of disciplines that he regards as sciences, but that do not fulfil the strict conception of a proper science. How do these two views go together? I argue that Kant employs a normative conception of science. To qualify as a science, a discipline must seek systematicity, order under rational principles, and apodictic certainty. Not all science is proper science, but all science aims to be proper science. My reading has two important advantages. It explains how Kant can hold that there is a broad domain of genuine science, while reserving a central place for the strict conception of a proper science. And it shows that, for Kant, science is a central cognitive activity whose investigation is integral to the study of human reason, knowledge, and cognition.


Worlds and Powers:

Reason in Kant’s Theory of Matter in the Metaphysical Foundations

Lydia Patton

(Virginia Polytechnic Institute and State University)

In the Metaphysical Foundations of Natural Science, Kant puts forth an account of material bodies, as substantia phaeonomenon endowed with moving forces (Friedman 2013). Commentators have said that Kant argues for material bodies as possessing causal powers (Warren 2001), and that Kant’s category of “reality”, when applied to matter, plays a role similar to that of substantial forms in the Scholastic tradition (Glezer 2018). The question inevitably arises: How can we prove a priori that a purely hypothetical ‘material body’ is endowed with a causal power or a moving force, or that it is real? This paper will investigate the roles played by reason, and by the understanding, in Kant’s answers to these questions in the MFNS. In so doing, we will untangle Kant’s complex notion of ‘completeness’ in logical and physical reasoning (McRobert 1995, Lu-Adler 2018). These investigations should shed light on Kant’s explanations of the phenomena of impenetrability and inertia. But they also involve the perplexing role of hypothetical reasoning and thought experiments in Kant’s Metaphysical Foundations. The paper concludes with an analysis of the difficult question: Does the MFNS restrict itself to providing an exposition of the concept of matter, or does it provide a theory of matter? What we might call the “Reichenbachian” reading of the MFNS, due to (Plaass 1994), (Friedman 2013), has it that the MFNS is concerned with the conditions of applicability of a priori reasoning about matter. I will argue that we can go further than this (and the seeds of this reading are found in Plaass and Friedman as well): the MFNS contains a theory, based on transcendental arguments, of the properties material bodies must have, and the laws they must obey, in order to be objects of experience.


Space, Time and Cause:

The Rational Determination of Nature in Kant and Einstein

David Hyder

(University of Ottawa)

The theory of space-time developed in Kant’s Kritik der reinen Vernunft and his Metaphysische Anfangsgründe der Naturwissenschaft connected to the “Kinematic Part” of Einstein’s “Zur Elektrodynamik bewegter Körper” (1905) via Leonhard Euler’s proof of invariance under Galilean transformations in the latter’s Analytical Mechanics (1736). The internal connection between the two space-time structures is that outlined in Minkowski’s “Raum und Zeit” (1909), meaning in turn that the Critique of Pure Reason’s 2nd Analogy of Experience is the dual of the Principle of Locality applied in the various Einstein-Podolsky-Rosen experiments. Thus Kant’s 3rd Analogy of Experience, which defines simultaneity through instantaneous causal interactions, should fall. I conclude by (1) assessing the significance of entanglement relations from the point of view of this “Berlin” physical tradition, (2) explaining the connection of these two theories of time to the emergence of the “phenomenology of time”, in Göttingen from 1905-1910, through the work of Husserl, Einstein, Minkowski, and their junior colleague, the mathematician and physicist Hermann Weyl.


The Unity of Reason and Its Varieties:

Systematicity in Chemistry, Psychology, and Natural History

Michael Bennett McNulty

(University of Minnesota)

The classic picture of Kant’s conception of scientific rationality is culled from his account of the metaphysics of body — natural science “properly so-called” — as developed in the Critique of Pure Reason and Metaphysical Foundations of Natural Science. According to this image, Kant’s model of scientific rationality is his top-down account of the grounding of rational physics in the categories and pure principles of the understanding. The “improperly so-called” natural sciences of chemistry, psychology, and natural history, however, provide us with a distinct, rival account of scientific rationality that proceeds from the bottom up (from empirical observations) and that is governed primarily not by the understanding but by the faculty of reason. This presentation details the various ways in which reason functions in these sciences and relates to empirical observations. Despite the apparent diversity of reason’s duties with respect to each of chemistry, psychology, and natural history, I argue that in each case reason makes possible certain non-logical types of unity that are preconditions for the possibility of bringing together empirical observations into genuine sciences.


Thought Experiments in Kant’s Philosophy: Types, Roles and Applications

Sergio Alberto Fuentes González

(Immanuel Kant Baltic Federal University, Kaliningrad)

Recent research on the history of thought experiments has drawn attention to the fact that it was Kant´s late scientific works that shaped the very notion of “Gedankenexperiment”. It has also been suggested that, beyond the scope of physics, thought experimentation has a key epistemological role in validating transcendental principles, as was stated by Kalin in his work (1972) “Kant’s transcendental arguments as Gedankenexperimente”. This paper analyzes how both types of “Kantian-transcendental” and “classic-scientific” thought experiments operate in concreto. In reading some of Kant´s arguments as thought experiments, it will be shown, it is possible to address and interweave other core issues, such as the roles of analogy and imagination within Kant´s critical philosophy. Evidence for this will be sought in works that include the “Universal Natural History and Theory of the Heavens”, the “Critique of Pure Reason” and “Metaphysical Foundation of Natural Science”.


Kant’s Pragmatic Reason in Contemporary Sociology:

A Third Way or a Methodological Impasse?

Alexey G. Zhavoronkov

(Institute of Philosophy of the RAS, Moscow; Immanuel Kant Baltic Federal University, Kaliningrad)

In the 20th century sociology, Kant had a big presence in many schools, be it critical rationalism, symbolic interactionism, or conflict theories. This, however, has changed with the gradual decline of sociological macro-level theories and with the overall shift in methodological trends. One of the currently dominant opinions, represented by the sociologist Ulrich Beck, is that Kant’s key ideas, for instance his normative idea of cosmopolitanism, are largely incompatible with the mainstream empirical-analytical approaches. In my paper, I will present an alternative view on the problem, beyond the sociological opposition of normativity and empiricism. Using Kant’s concept of pragmatic reason, a cornerstone of his pragmatic anthropology, I will discuss the question of whether we can see a pragmatic approach as a possible third way in modern sociology and whether this third way can help us in clearing some sociological issues with Kant’s approach and in building a foundation for an anthropologically grounded sociology.


The Concept of Number Through the Lens of the Kantian Research Program in Current Neuroscience

Valentin A. Bazhanov

(Ulyanovsk State University)

The goal of my presentation will be the analysis the number through the lens of Kantian program in modern neuroscience. Kantian ideas of the a priori nature of certain mathematical categories related to the status of space and time (geometry and arithmetic), were reassessed as the result of the intensive progress of current cognitive neuroscience. The discovery of the ’sense of number’ and ‘place cell’s (brain’s navigational system)’ open the path to reconsider the old Kantian judgments related to certain a priori constructions of mathematics. The ontogenetic foundations of these constructions speak in the favor for not the metaphorical, but the strategic nature of the Kantian studies in modern neuroscience.

In the context of these studies, we can claim their proto-arithmetic traits. In the case of humans, mathematical abilities are largely independent of the language, and their development from the neonate period significantly increases the likelihood of successful mathematical talent to flourish in the future. We draw attention to the interdependence of the developing brain, social, and cultural milieu, which manifest itself through the process of acculturation of the brain and neural determination of culture. This type of interaction paves the path for introducing the concept of transcendentalism of the activity type.


The Problem of Unity and Disunity of Science: Kant vs. Kuhn

Leonid Yu. Kornilaev

(Immanuel Kant Baltic Federal University, Kaliningrad)

The problem of unity and unification are of great importance in the philosophy of science. Why should science be united or, on the contrary, cannot be so? An inherent stage in the evolution of this problem was the Kantian doctrine of systematicity, which in many respects laid the foundation for the possibility of creating a unified scientific image of the world in general. There are many conceptions in the philosophy of science that defend both the unity of science and its fundamental impossibility. In the XXth century one of the most notable doctrine of disunity of science was T. Kuhn’s anti-reductionist conception. In my presentation, I analyze the standpoints of Kant and Kuhn relying on a number of key issues: the concept of unity, justification of the need for unity/disunity, formation of new sciences, the role of philosophy in the development of the unity/disunity of science.


Kantian Elements in Metzger’s and Kuhn’s Historiographies of Science

Karin de Boer (Catholic University of Leuven)
Pavel Reichl (Heidelberg University)

While Kant is not mentioned in The Structure of Scientific Revolutions, Kuhn in the early 1990s referred to his own work as an instance of “post-Darwinian Kantianism” (2000: 104). In response to a paper by Friedman, he aligned his own theory with Kant’s insofar as the latter conceived of a priori categories as “constitutive of possible experience” without dictating “what that experience must be” (2000: 245). In a 1995 interview, moreover, Kuhn mentions that reading Kant as a student “was a revelation” (2000: 264). Be that as it may, we hold that this early encounter with Kant does not explain the extent of the affinities between Kant and Kuhn’s conceptions of scientific rationality. Various commentators have pointed to similarities between Kuhn’s project and that of neo-Kantians such as Cassirer (Friedman 2010, Ferrari 2012). However, there is no evidence that Kuhn was familiar with Cassirer’s work at the time he was working on Structure. We do know, by contrast, that Kuhn took inspiration from French authors who during the early decades of the twentieth century turned to the history of the sciences to capture forms of scientific rationality in the making, esp. Meyerson, Metzger, and Koyré (Kuhn 1962/1970: vii-viii). We also know that their views were informed at least in part by neo-Kantian readings of Kant. In this paper, we aim to shed light on the Kantian elements of Kuhn’s historiography of science by comparing the relevant aspects of Structure to the pioneering yet underinvestigated work carried out by Hélène Metzger between the first and second world wars. In doing so, we will take into account her relationship to the neo-Kantian approaches to science that flourished in France at the time.


Ferrari, M. (2012), ‘Between Cassirer and Kuhn. Some Remarks on Friedman’s Relativized A Priori’, Studies in History and Philosophy of Science 43, 18-26.

Friedman, M. (2010), ‘Ernst Cassirer and Thomas Kuhn: The Neo-Kantian Tradition in the History and Philosophy of Science’, in: R.A. Makkreel and S. Luft (eds.), Neokantianism in Contemporary Philosophy (Bloomington: Indiana University Press), 177-191.

Kuhn, T. (1962/1970), The Structure of Scientific Revolutions (University of Chicago Press).

Kuhn, T. (2000), The Road since Structure: Philosophical Essays, 1970–1993, with an Autobiographical Interview, edited by J. Conant and J. Haugeland (Chicago / London: University of Chicago Press).