Séminaire │ MEPHISTO

Nous entendrons une conférence on-line de Sami Pihlström (Helsinki, Finland), Professor of Philosophy of Religion at the University of Helsinki

Titre : Abstract: "Putnamian Transcendental Arguments"

Given Hilary Putnam’s deep interest in the critical philosophy of Immanuel Kant, it is surprising that he never sympathized with his interlocutors’ proposals to compare his views on realism and idealism to Kant’s transcendental idealism. In this paper, I am trying to interpret Putnam as a Kant-inspired transcendental philosopher. I will confine myself to an investigation of a selection of Putnam’s (or, rather, Putnamian) transcendental arguments. I will argue that some of these arguments offer us useful philosophical resources for developing a pragmatic non-reductive naturalism – i.e., a version of transcendental naturalism, or pragmatically naturalized transcendental philosophy. The paper will briefly discuss five transcendental arguments: (i) the Brains in a Vat argument; (ii) the argument against metaphysical realism based on conceptual relativity; (iii) the argument for realism rejecting relativism and other non-realisms; (iv) the argument against reductive naturalism (or physicalism); and (v) the argument for the entanglement of fact and value.

vendredi 26 septembre 2025 ; 14h-16h

Michel Bitbol (CNRS, Archives Husserl, Paris, France) will give an online talk entitled

"Transcendental epistemologies and probabilism"

in the context of UCLouvain’s new monthly seminar MEPHISTO ("MEtaphysics and PHIlosophy of Science: Transcendental Orientations").

Abstract: "Transcendental epistemologies and probabilism" 

Transcendental epistemologies, in their Kantian and Husserlian varieties, can be characterized by two basic tenets: (1) It is possible to regress from objects to the preconditions for their givenness, and (2) The constitution of objects involves anticipating phenomena—both intellectually and practically—through structural assumptions that conform to these preconditions. Anticipation is the key concept here, one to which Husserl ascribes an ambivalent status in his Crisis. According to Husserl, anticipating future appearances is a basic function essential to life. But this is also, unfortunately, the task to which modern natural sciences restrict themselves—far from the ideal of genuine theoretical knowledge that had inaugurated the project of science. In this talk, I wish to show that when its anticipatory status is fully embraced by physical science in the form of probabilism, an about-turn occurs—bringing us closer to Husserl’s ideal of a comprehensive science wholly aware of its own foundation, rather than distancing us from it. This paradoxical development is not difficult to grasp. Indeed, with probabilism, we move away from the deceptive traditional static, demiurgic, objectivistic, naturalistic, third-person, and falsely omniscient view of science. Instead, we move toward a dynamic, practical, first-person, engaged, and inherently finite conception. In this new framework, probability is no longer regarded merely as a mathematical tool reluctantly employed to cope with temporarily incomplete knowledge. Rather, it emerges as the foundational principle of all cognition, finally revealed by the most advanced scientific developments. In this light, quantum physics becomes the paradigm of a new science – one that (unlike classical physics) can no longer ignore its transcendental preconditions.

Please note that this conference will be streamed live on the youtube channel of the CEFISES. No registration required.

Friday, 24th October 2025, from 14h to 16h CEST (1h of talk + 1h of Q&A)

ISP - Louvain-la-Neuve (Belgium), Place Cardinal Mercier 14, Salle Ladrière + live on youtube

Abstract: "Phenomenology and Wave Function realism"

This talk reexamines wave function realism (WFR) through the lens of phenomenology. We begin by situating WFR within the broader debate about the ontology of the quantum state and the temptation to "read  off" metaphysics from mathematical formalism. Against this background, we turn to the London–Bauer interpretation (LBI), the most explicit attempt to interpret quantum mechanics through phenomenological categories. On this view, the measurement transition is not a physical  discontinuity but a reflective articulation of objectivity, and the wave function formally encodes the horizonal structure of world-givenness. We develop this idea by reconfiguring the notion of realism itself: not as objectivist, but as correlational and transcendental. The resulting  picture suggests that quantum mechanics, rather than depicting a world "minus observers," mathematically articulates the very correlation through which a world becomes manifest at all.

from 14h to 16h CEST (1h of talk + 1h of Q&A)

ISP - Louvain-la-Neuve (Belgium), Place Cardinal Mercier 14, Salle Ladrière

+ live on youtube

Kristina Engelhard (Trier University, Germany) will give a talk entitled "Powers BSAs and Cognitive Capacities. A Powerful Capacitist Theory of Laws of Nature" in the context of UCLouvain’s new monthly seminar MEPHISTO ("MEtaphysics and PHIlosophy of Science: Transcendental Orientations").

Abstract: "Powers BSAs and Cognitive Capacities. A Powerful Capacitist Theory of Laws of Nature"

This talk sketches and explores the outlines of a new theory of the laws of nature, according to which laws, understood as both law facts and law propositions, can be grounded on two kinds of powers: physical and cognitive powers. This theory is called the Powerful Capacitist Theory of Laws (PTLPC). This approach combines an ontological and an epistemological perspective on laws. One version of this account is Powers BSA, which has recently been discussed in the literature. Like the Powers BSA, the PTLPC can explain epistemic features connected to the laws of nature, such as the relationship of laws and theories to scientific practices. However, it is superior to recent Powers BSAs in that it can provide a unified and systematic account of this dualism. In part one I discuss the PBSA account and Friend's objection to; I then show in part two that a powers theory of laws including powerful capacitism — the view that there are cognitive powers bringing about cognitive outputs such as intuitions, propositions, inferences, and theories — is unaffected by Friend's objections. Section three sketches a metaphysics of cognitive powers. Section four outlines how a powers theory including powerful capacitism grounds the laws of nature. Finally, section five concludes the results of this investigation.

from 14h to 16h CEST (1h of talk + 1h of Q&A)

ISP - Louvain-la-Neuve (Belgium), Place Cardinal Mercier 14, Salle Ladrière

+ live on youtube

talk entitled "Neo-Kantian Epistemology and Pragmatic Naturalization: The Case of Hermann von Helmholtz"

from 14h to 16h CET (1h of talk + 1h of Q&A)

ISP - Louvain-la-Neuve (Belgium), Place Cardinal Mercier 14, Salle Ladrière + live on youtube

Abstract: "Neo-Kantian Epistemology and Pragmatic Naturalization: The Case of Hermann von Helmholtz"

This talk examines how the Vienna Circle’s distinction between the context of justification and the context of discovery informs Michael Friedman’s interpretation of Hermann von Helmholtz’s nineteenth-century neo-Kantian epistemology and —drawing on Sami Pihlström’s work— proposes an alternative model of transcendental naturalism as a “pragmatically naturalized transcendental epistemology”. After introducing the anti-metaphysical Viennese distinction— commonly attributed to Hans Reichenbach—I argue that Michael Friedman’s reading of Helmholtz, centered on the problematic geometrical definition of the free mobility of rigid bodies, maintains a principled separation between the reality of external objects, shaped by human psychophysical dispositions, and scientific objectivity. The latter depends on the strict conformity between standards of measurement and the magnitudes measured, on causality as a regulative condition for the comprehensibility of nature, and on a practical choice among different equipossible ontological frameworks.

In response, I develop a broader pragmatically naturalized transcendental interpretation of Helmholtz, grounded in a naturalized epistemology that carries forward Kant’s critical and constructivist project from within the epistemic constraints of scientific practice and human psychophysical embeddedness. These constraints, which require revising the fixed, necessary, and universal Kantian a priori of categories and cognitive faculties, frame a functionalist account of cognition—manifest in Helmholtz’s theory of sign perception and unconscious predictive inference—as a system of practical, goal-directed adaptive mechanisms that presuppose causality as a trustworthy regulative condition of possibility. The view thus combines empirical realism regarding the external constructed world with transcendental dependence on the conditions of cognition and conceptual practices, making it “practice-oriented enough to be ‘pragmatist’ and condition-oriented enough to be ‘transcendental’” . Therefore, my study resituates Friedman’s interpretation of Helmholtz’s physical geometry within a pragmatic horizon—one that remains critical of anti-metaphysical positions. From this vantage point, a long-overdue rapprochement between the early nineteenth-century proponents of a “return to Kant” and contemporary analytic Kantianism becomes not only possible but philosophically fruitful.

talk entitled "The German Copenhagen School: From Heisenberg to Mittelstaedt and Scheibe" 

Abstract: "The German Copenhagen School: From Heisenberg to Mittelstaedt and Scheibe"

The group of physicists and philosophers around Werner Heisenberg may be called the German Copenhagen School. Heisenberg developed his epistemic interpretation of quantum mechanics under the influence of Niels Bohr. Later, his philosophical views shifted to a Neo-Kantian relative a priori. These views and the related approach of Carl Friedrich von Weizsäcker are the common background of the philosophy of physics developed by Erhard Scheibe and Peter Mittelstaedt, who dominated German philosophy of physics in the second half of the 20th century. Partly due to a lack of translations, partly due to a mainly historical significance attributed to Kant’s theory of nature, Mittelstaedt’s and Scheibe’s work received relatively little attention in the international philosophy of science.

Scheibe and Mittelstaedt took distinct routes into the philosophy of physics. Their approaches to physics substantially differ, but there are also important parallels. Mittelstaedt elaborated a Kantian approach from the beginnings, making use of Kant’s conditions of possible experience to investigate the semantics and ontology of modern physics and to understand conceptual change in physics (Mittelstaedt 1964, 1968, 2009, 2013). Scheibe primarily analysed the axiomatic structure of quantum theory, the problem of its incommensurability with the theories of classical physics, and the consequences for a philosophical theory of reduction (1964, 1973, 1997/99). His Kantianism showed up late, in a talk Between Rationalism and Empiricism: The Path of Physics that later gave title to the collection of his papers (Scheibe 1994, 2001). Scheibe claimed that the epistemological attitudes of prominent physicists had much in common with Kant’s views about the relation between theory and experience, a topic he investigated further in his last book (2007). From a systematic point of view, it is particularly interesting to compare Scheibe’s many-faceted theory of reduction (1997/99) and Mittelstaedt's rational reconstruction of physics (2013).

Title: "Relativity: a line that can be traced through centuries?"

Abstract: It is generally thought that the principle of relativity had long served mechanics when, around 1900, Poincaré and Einstein seized upon it to reformulate the electrodynamics of bodies in motion and to develop what we now call the theory of relativity. In reality, most physicists before Relativity did not regard Galilean relativity as a principle but rather as an empirical law (Galileo) or as a theorem (Newton and most of his successors). Yet it is true that in the seventeenth century Christian Huygens inaugurated a lasting tradition of deriving mechanical laws from constructive principles of relativity. The plural is necessary here, because since Newton two types of relativity were considered: on the one hand Galilean invariance, asserted by Galileo, and on the other a more general invariance with respect to a global acceleration of the system of bodies (somewhat like in Einstein’s equivalence principle). We will see how the principles of relativity flourished in the hands of Euler, d’Alembert, and Laplace, then became the basis for a popular derivation of Newton’s law of acceleration in nineteenth‑century French physics textbooks. It turns out that both Poincaré and Einstein were aware of this tradition, and that Poincaré drew from it the name principle of relative motion, later altered to principle of relativity. By giving this principle a major architectonic role, both authors were distant heirs of the great Huygens.

Friday, 10th April 2026, from 14h to 16h CEST (1h of talk + 1h of Q&A)

ISP - Louvain-la-Neuve (Belgium), Place Cardinal Mercier 14, Salle Ladrière

+ live on youtube

"Measurement, Prediction, and Fact"

Abstract:

Measurement is taken to provide knowledge of the way things are, and not merely of the way things would or could be under some specified set of conditions. In this regard, measurement is epistemically distinct from other forms of quantitative estimation, such as prediction and calculation. Nonetheless, measurement depends on theoretical and statistical assumptions and on idealized models that are themselves only testable through further measurements. This introduces a threat of infinite regress against attempts to justify the factual status of measurement results. I offer a novel pragmatist solution to the riddle of factuality. According to this solution, the presentation of measurement results as factual statements is a pragmatic choice. This choice is justified, not by any special ability of measurement to detect and isolate empirical structures, signals, or causes, but by the convenience of expressing knowledge claims in the most modular way that is fit for the purpose at hand.

Friday, 5th June 2026, from 14h to 16h CEST (1h of talk + 1h of Q&A)

live on the youtube channel of the CEFISES

or for those in Louvain-la-Neuve (Belgium):

Place Cardinal Mercier 14, Salle Ladrière.

No registration required.