Marco Buzzoni

The paper outlines a critical history of the concept of TE from a broadly Kantian viewpoint. The thread of our discussion has been Kant's position on the nature of the a priori and how each neo-Kantian theory of TEs can be understood in terms of its own position on this issue. Section 2 examines some aspects of Kant's philosophy that are related to today's debate on TEs. Section 3 is devoted to the precursors of neo-Kantian accounts of TEs, with a special emphasis on Ørsted's account. This author wavers between two positions: sometimes he claims that TEs are merely the hypothetical aspect of REs while other times he assigns to them the capacity of determining a priori some fundamental laws of natural science. The latter position recalls the "material" aspect of the Kantian a priori, a notion which was abandoned by the philosophy of science at the end of the nineteenth century. This is probably the main reason Ørsted's point of view had no real influence on the historical development of the concept of TE and why some recent Kantian or neo-Kantian accounts of TE depart from Ørsted's concept of the a priori. I, on the other hand, have defended an interpretation of the a priori as purely functional by retaining the necessary and universal character of Kant's a priori while rejecting the material a priori, since content can be given only by experience. On this view, TE and RE are complementary in a sense similar to the complementarity of form and matter in Kant: TEs without REs are empty; REs without TEs are blind. On the other hand, Yiftach Fehige has defended a relativized and contingent notion of the a priori which has been recently advocated by many authors, notably by Michael Friedman. Unlike myself, Fehige rejects the universality and necessity of Kant's a priori but retains the idea that the a priori, as a constitutive element of experience, is endowed with material content that may be made explicit by thought experimentation.

Hempel’s account of thought experiments has been discussed only by a very few authors and, for the most part, with rather cursory remarks. Its importance, however, is not only historical, but also systematic theoretical, because it involves the distinction between discovery and justification, a main pillar of neopositivistic philosophy of science. Hempel raised the question whether thought experiments constitute a methodological component of scientific research or, on the contrary, are merely a heuristic-psychological device for obtaining and/or transmitting new ideas. While conceding a few exceptions in the natural sciences, he argued that thought experiments always have a heuristic character in the social sciences. There is however a fundamental tension in Hempel’s conception of thought experiments, between the thesis of methodological monism and the neopositivistic dichotomy discovery/justification. On the one hand, on the basis of the unity of scientific method, Hempel admits a difference only in degree between the natural and the human sciences, but on the other hand, he draws a principled distinction between thought experiments of the human sciences (which have only a greater or lesser heuristic value) and those of the natural sciences (which may have also a cognitive-justificatory value). If one assumes the unity of method in the minimal sense in which no scientific knowledge can renounce intersubjective controllability, this tension can be removed either by rejecting the discovery/justification dichotomy or by interpreting it differently. Here, following the second path, two senses of the dichotomy are distinguished, one of which must be accepted, while the other rejected. This removes the internal tension in Hempel’s conception of thought experiments and suggests the thesis that any plausible thought experiment, both in the natural and the human sciences, must already contain some justification, implicit or explicit, of the theoretical hypotheses that they formulate.

Der Neue Experimentalismus musste sich angesichts seines Gegensatzes zwischen experimentellen Praktiken und grundlegenden Theorien mit dem Problem der Beziehung zwischen der Einmaligkeit der ersteren und der Allgemeinheit der letzteren auseinandersetzen. Andere Autoren (von Charles A. Baylis und Nelson Goodman bis Catherine Elgin) haben das Konzept der Exemplifikation verwendet, um die Beziehung zwischen partikulären und universellen/allgemeinen Begriffen oder Gesetzen zu klären. Es stellt sich jedoch die Frage, ob sie zwar einen Gesichtspunkt andeuten, der neue Aspekte des Problems beleuchten kann, das Problem selbst aber nicht lösen. In diesem Artikel wird auf der Grundlage von Überlegungen, die an anderer Stelle entwickelt wurden, sowie in Anlehnung an eine Anregung von Aristoteles vorgeschlagen, den Begriff der Exemplifikation mit dem Problem der Induktion und der Abduktion zu verknüpfen, die hier als Bezeichnung für eine Vielzahl methodischer Verfahren verstanden werden, die darauf abzielen, eine kognitive Beziehung zwischen der Reproduzierbarkeit wissenschaftlicher Begriffe oder Gesetze und der Konkretheit, der Lokalität und dem situierten Charakter experimenteller Praktiken herzustellen. Eine notwendige Voraussetzung für die Lösung des durch diese Beziehung aufgeworfenen Problems ist die Unterscheidung zwischen zwei Bedeutungen − einer reflexiv-transzendentalen und einer genetisch-methodologischen − des Begriffspaares Entdeckung/Rechtfertigung. Dies wirft gleichzeitig Licht auf das Problem der Induktion sowie auf das Problem des Verhältnisses zwischen der Universalität wissenschaftlicher Gesetze und dem stets lokalen und situierten Charakter experimenteller Praktiken. Der letzte Teil des Artikels zeigt, wie diese Schlussfolgerungen auch für Gedankenexperimente gelten, indem auf John Nortons Auffassung eingegangen wird.

All the most important epistemological and ontological theses of Kuhn's theory of science depend to a decisive extent on corresponding ideas of Wittgenstein's theory of meaning. The semantic and ontological assumptions that determine the main trend of Kuhn's epistemology consist, respectively, of a theory of meaning as use or application of empirical terms to nature and an ontology that conceives the real as a continuous essentially amorphous and undifferentiated, in which only language and its rules can insert order and regularity, In Kuhn's theory of science, however, beside this main trend of thought, there is another one, by far secondary, which moves towards a realistic conception of scientific theories, although it usually stops halfway, assuming the aspect of an unsustainable and unoriginal indirect realism. After highlighting the oscillations and internal difficulties not only of Kuhn's epistemology and methodology, but also of the Wittgensteinian theory of meaning, the final part of the volume outlines a realistic conception of scientific knowledge that takes as its foundation the intrinsically cognitive nature of instrumental operations and tries to provide a satisfactory response to Kuhn's challenge and, in particular, to his thesis of incommensurability. From this point of view, the use and reference of scientific terms or theories are constitutive and inseparable moments of their meaning, and refer to an internally structured relational reality.

The first part of this paper discusses two important meanings of robustness and shows their essential connection with the notion of intersubjective reproducibility. As I shall maintain, robustness in both senses of the term is intimately connected with the notion of scientific experiment. This is the important element of truth of the mechanistic systems approach, which explains events as products of robust and regular systems and processes. In the second part of this paper I shall show that the concept of robustness of a mechanism, if applied to biological systems, is one-sided and incomplete without a heuristic˗methodical reference to final causes, even though the assumption of the teleological point of view is justified in biology only to the extent that we use it as a counterfactual artifice, capable of bringing to light causal relations which have a robustly reproducible content. In this way, the reflexive, typically human concept of purposefulness may be employed to investigate living beings scientifically, that is, in an intersubjectively testable and reproducible way, to discover mechanisms in living systems which are robust in both senses of the word.

The conventional interpretation that Duhem condemned outright any type of thought experiment in Mach’s sense should be, at least in large part, rejected. There are some interesting remarks made by Mach and Duhem that suggest a very different reading. In this paper I shall take up and develop these remarks, which lead to the conjecture that Duhem’s criticism was not intended to be a complete rejection of thought experiments but a completion and supplement of Mach’s theory. Duhem, while retaining the core idea of Mach’s theory – according to which thought experiments cannot break free from the ultimate authority of real world experiments –, laid particular emphasis on the perils of thought experiment, which Mach had overlooked or, at least, underestimated.

The main purpose of this paper is to investigate some important aspects of the relationship between thought experiment and computer simulation, from the point of view of real experiment. In the first part of this paper, I shall pass in critical review four important approaches concerning the relationship between TE and CS. None of these approaches, though containing some important insights, has succeeded in distinguishing between CS and TE, on the one hand, and REs, on the other. Neither have they succeeded in distinguishing TEs and REs. In Sect. 5, the paper briefly outlines an account of CSs as compared with TEs that takes REs as a central reference point. From the perspective of the analysis of the empirico-experimental intensions of the concepts of TE, CS, and RE—considering their empirical content and actual performance within a discipline—the attempts to find a distinction in logical kind between TEs, CSs and REs breaks down: for every particular characteristic of one of these notions there is a corresponding characteristic in the two others. From an epistemological-transcendental point of view, the only difference in kind between TEs and CSs consists in the fact that any simulation, even a computer one, involves a kind of real execution, one that is not merely psychological or conceptual. In TEs the subject operates concretely by using mental concepts in the first person; in contrast, real experiments and simulations involve an ‘external’ realisation. As shown in Sect. 6, this manifests itself in the higher degree of complexity often found in CSs as compared with TEs.