Marco Buzzoni

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 purpose of this article is to examine two important issues concerning the agency theory of causality: the charge of anthropomorphism and the relation of simultaneous causation. After a brief outline of the agency theory, sections 2–4 contain the refutation of the three main forms in which the charge of anthropomorphism is to be found in the literature. It will appear that it is necessary to distinguish between the subjective and the objective aspect of the concept of causation. This will lead, in section 5, to contrast two kinds of anthropomorphism, one which has been rightly rejected by modern science and one which is fully compatible with the objective reality of the causal processes. Finally, section 6 will apply the preceding considerations to simultaneous causation. On the one hand, in a basic sense, there can be no simultaneous causal relations. On the other hand, simultaneous causation arises when we consider the natural change by abstracting from the agent and from her/his projects of interven..

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.

Marco Buzzoni Gödel, Searle, and the Computational Theory of the (Other) Mind According to Sergio Galvan, some of the arguments offered by Lucas and Penrose are somewhat obscure or even logically invalid, but he accepts their fundamental idea that a human mind does not work as a computational machine. His main point is that there is a qualitative difference between the principles of the logic of provability and those of the logic of evidence and belief. To evaluate this suggestion, I shall first compare it with Searle’s concept of “intentionality”, and then introduce a distinction between two different senses of intentionality: a reflexive-transcendental sense and a positive (that is, historical empirical or formal logical) one. In the first of these senses, the nature of human reason is such that we have no idea how a real material system – or the corresponding formal one – could instantiate it. However, although this will turn out to be an important element of truth in Searle’s and Galvan’s conception, it does not exclude the opposite truth of Turing’s functionalism: because intentionality, intuition, vision or insight – taken in their reflexive-transcendental sense – are simply invisible to the scientific eye, a man and a machine (or a robot) that is and one that is not endowed with intentionality are de facto indistinguishable from a strictly scientific point of view. For this reason, we might eventually be entitled, or even — by the practical precautionary principle – morally obliged, to attribute minds to machines.

The conventional interpretation that Pierre Duhem condemned outright any type of thought experiment in Ernst Mach’s sense should be, at least in large part, rejected. Although Duhem placed particular emphasis on the perils of thought experiments that Mach had overlooked or at least underestimated, he retained the core idea of Mach’s theory, according to which thought experiments cannot break free from the ultimate authority of real-world experiments. This similarity between Duhem’s and Mach’s views about thought experiments is not the only one. Just as there was in Duhem’s criticism of “expériences fictives” a tendency leading him to give voice to one of Mach’s basic empiricist claims, so also there was in Mach’s interpretation of thought experiments a tendency in the direction of Duhem’s conventionalism. If Mach’s and Duhem’s conceptions of thought experiments are compared, there results an importantly similar, although not identical, tension that should properly be taken into account in the more general comparison between Mach and Duhem.

Why, for such a long time, has there been no Kantian point of view among the most influential theories about thought experiments? The primary historical reason – the main trends in the philosophy of science have always rejected the existence of a priori knowledge – fits a theoretical reason. Kant oscillated between two very different views about the a priori: on the one hand, he attributed to it a particular content, whereas on the other hand he insisted on its purely formal character. The first interpretation of the a priori was one-sidedly developed by Ørsted and led to his untenable notion of thought experiment. The other interpretation, however, can be further developed into new Kantian theories of thought experiments in the natural sciences and in philosophy.

Within Popper's philosophy of science there is a tension between two different and opposite tendencies of thought: one consists in a decisive critique of the neopositivistic philosophy of science, the other preserves instead some assumptions of gnoseology and ontology of Wittgenstein's Tractatus. The attempt to resolve the tension between these two tendencies of thought constitutes the spring that has guided the internal development of Popperian epistemology, from the falsificationism of Die beiden Grundprobleme der Erkenntnistheorie and Logik der Forschung to the more recent theory of World 3. The thesis of a co-presence in Popper's thought of neo-positivistic and antíneopositivistic themes is here understood in a radical sense, which invests the gnoseological and ontological foundations of Popperian epistemology. The development of this thesis takes place by discussing the relevant literature of both the English and German linguistic area. Finally, the author has attempted to enucleate from Popperian epistemology those elements of thought that, if properly developed, would have allowed a re-reading in operational terms of the notion of scientific objectivity and would have made superfluous any Platonic theory of science, such as the Popperian theory of World 3, plagued by serious internal difficulties.

This work interprets the notion of thought experiment (TE) from the viewpoint of a functional reading of the a priori, that is, an a priori that is devoid of any particular content. It is true that Kant ascribes some content to the (synthetic) a priori, but only a functional reading of the a priori agrees with the spirit of Kant's philosophy and can be used for developing a consistent account of TEs. On the basis of this concept of the a priori, an account is developed that mediates between Brown and Norton by considering TEs from two distinct but connected points of view: transcendental and operational. On the one hand, the account is transcendental in a very usual sense of the word: TEs are the condition of the possibility of real world experiments (REs) because, without the a priori capacity of the mind to reason counterfactually, we could not devise any hypothesis and would be unable to plan the corresponding RE that should test it. This capacity underpins the distinction in principle — a properly transcendental distinction — between TEs and REs. But while there is a distinction in principle between TE and RE on the transcendental level of the a priori capacity of the mind to reason counterfactually, the exclusively func¬tional character of the a priori entails that, on the operational-methodological level, TEs —considering their empirical content and actual performance within a discipline — are and function essentially like REs.

On the relation between experiment and thought experiment in the natural sciences. To understand the reciprocal autonomy and complementarity of thought and real experiment, it is necessary to distinguish between a ‘positive’ (empirical or formal) and a transcendental perspective. Empirically and formally, real and thought experiments are indistinguishable. However, from a reflexive-transcendental viewpoint thought experiment is at the same time irreducible and complementary to real experiment. This is due to the fact that the hypothetical-anticipatory moment is in principle irreducible to physical reality—even though it refers to physical reality and is bound with the empirical use of our understanding. The presence of counterfactuals is the condition of the possibility for thought experiments to become in principle real ones, by means of a series of technical realisations that gradually approximate the idealisations that they contain.

The terms “perspectivism” and “perspectivalism” have been the focus of an intense philosophical discussion with important repercussions for the debate about the role of mechanisms in scientific explanations. However, leading exponents of the new mechanistic philosophy have conceded more than was necessary to the radically subjectivistic perspectivalism, and fell into the opposite error, by retaining not negligible residues of objectivistic views about mechanisms. In order to remove this vacillation between the subjective-cultural and the objective-natural sides of mechanisms, we shall raise the question about theory-ladenness over again and interpret it in its connection with the technical–experimental nature of scientific knowledge, as affirming the perspectival character of scientific knowledge: It is because of the character at once theory-laden and practice-laden, i.e. technique-laden, of our putting questions to nature that empirical reality must be investigated from particular perspectives: nature can be known scientifically only from a potentially infinite number of perspectives or theoretical points of view, concretely exemplified by mechanisms or experimental ‘machines’ that allow specific access to specific aspects of sensible reality.

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 operational perspective here defended permits a reflexive-transcendental point of view that sharply distinguishes the two concepts, while, at the same time, maintaining the connection between them. On the one hand, simply imagining that the experimental apparatus, counterfactually anticipated in a thought experiment, has really been constructed is sufficient to erase any difference between thought and real experiments. On the other hand, this very ‘imagining’, this capacity of the mind to assume every real entity as a possible entity, underpins the difference in principle – a properly transcendental difference – between thought and real experiments. This difference, however, implies the intimate association between experiment and thought experiment: All thought experiments must be thought of as translatable into real ones, and all real experiments as realisations of thought ones. What thought experiments have over and above real experiments is the mere fact that they exist in a purely hypothetical sphere; what real have over and above thought experiments is the mere fact that they overstep the sphere of the possible, in the experiment’s real execution.

Thought experiments de facto play many different roles in biology: economical, ethical, technical and so forth. This paper, however, is interested in whether there are any distinctive features of biological TEs as such. The question may be settled in the affirmative because TEs in biology have a function that is intimately connected with the epistemological and methodological status of biology. Peculiar to TEs in biology is the fact that the reflexive, typically human concept of finality may be profitably employed to discover mechanical-experimental causal relations in all living beings—with the obvious caveat that we do not hypostatise and interpret this concept as an ontological quality, since this would land one in an implicitly animistic, pre-Galilean view of nature. From a methodical point of view, the concept of finality is an essential assumption as well as a powerful heuristic tool in the practice of biology, that is, in the investigation of living beings in an intersubjectively testable and reproducible way.

Hermeneutic and anti-hermeneutic sides in the debate about psychoanalysis are entangled in an epistemological and methodological antinomy, here exemplified by Grünbaum's and Spence's paradigmatic views. Both contain a partial element of truth, which they assert dialectically one against the other (§§ 1 and 2). This antinomy disappears only by reconciling an operationalist approach with man's ability to suspend the effectiveness of the‘laws’ applied to him (§ 3). The hermeneutic way in which the technical-operational criterion of truth works in psychoanalysis demands that clinical and extra-clinical testing methods work synergically, through a fruitful self-correcting strategy, grounded on the very psychoanalytic object: the unconscious (§ 4).