Most disciplines make use of thought experiments, but physics and philosophy lead the pack with heavy dependence upon them. Often this is for conceptual clarification, but occasionally they provide real theoretical advances. In spite of their importance, however, thought experirnents have received rather little attention as a topic in their own right until recently. The situation has improved in the past few years, but a mere generation ago the entire published literature on thought experiments could have been mastered in a long weekend. Now the subject is beginning to flourish. Given the relative newness of the field, it might be useful to have several examples at one’s finger tips, so a number of great ones will be described. Attention will also be drawn outside physics and philosophy. In mathematics there is something analogous to thought experiments -- visual reasoning and picture proofs. I will look briefly at this class of thought experiments and try using them to make a case for possibly settling the continuum hypothesis. After this, I will return to thought experiments in the sciences and propose an account of how they work. Finally, I will end with a sketch of a topic I am currently working on, a kind of progress report which, I hope, will be an inducement to others.

I explore the possibility that there are interesting and illuminating paralleIs to be drawn between issues central to the philosophical literature on scientific thought experiments (TE’s) and issues central to the phlilosophical literature on standard fictional narratives. I examine three related questions: (a) To what extent are TE’s (like) standard fictional narratives? (b) Is the understanding of TE’s like the understanding of standard fictional narratives? (c) Most significantly, are there illuminating paralIeIs to be drawn between the ‘epistemological problem’ of TE’s in science, and epistemological problems that attend some of the cognitive claims made for standard works of fiction? If so, are strategies used to defend the epistemic virtues of TE’s equally available to defend the cognitive claims of works of fiction? In addressing the third of these questions, I spell out the range of responses elicited by the epistemological problern of TE’s in science and suggest that at least one of this responses might bear upon the credibility of the cognitive claims of fiction.

Recent debates about thought experiments have focused on a perceived epistemological problem: how do thought experiments manage to provide knowledge when they yield no new empirical data? A bold answer to this question is provided by James Robert Brown’s platonisrn, according to which a certain class of thought experiments allow a sort of intellectual perception of laws of nature, understood as relations between universals. I suggest that there are three main problems with platonism. First, it is restricted to a very small class of thought experiments; hence, it largely fails to address the general epistemological problem. Second, it is not quite clear what it is supposed to explain. Third, its explanatory value in any case seems dubious, since the mechanisms it postulates (i) appear to raise issues more ditficult than what they would explain, and (ii) seem to obviate the very need for conducting thought experiments. I also argue that it fails to give an accurate account of Brown’s flagship example, Galileo’s thought experiment on falling bodies. In conclusion, I suggest that although platonism about thought experiments is an exciting thesis, it is at present unconvincing.

In The Laboratory of the Mind, James Brown considers some of the Kuhn’s thesis in “A Function for Thought Experiment”. I will question one of Brown’s conclusions, namely his interpretation according to which Kuhn maintains that from thought experiments we learn about our conceptual scheme and only derivatively about the world. I arn inclined to think that this particular interpretation does not accurately represent Kuhn’s wording. Accordingly, I will outline some of the issues concerning the relation between ‘learning about the concepts’ and ‘learning about the world’, which is, as Brown states, the field of disagreement between him and Kuhn. And finally, I will consider whether Kuhn’s ‘incommensurability thesis’ is in contradiction with ‘thought experiment thesis’, as Brown seems to imply.

In one of the most influential empiricist account on the epistemic nature of thought experiments John Norton proposes a challenge: that no thought experirnent in science could be found that cannot be logically reconstructed as an argument. Norton’s account has two main theses, the epistemic thesis that all information about the physical world delivered through a thought experiment comes solely frorn experience and the reconstruction thesis that all thought experiments could be reconstructed as arguments. In the present paper I argue that in at least sorne cases Norton’s theses are incompatible with each other and therefore their combination could not form a reliable account. I try to show that sometimes the experience available could not justify the conclusion of a thought experiment and even contradicts it. I suggest an analysis of Einstein’s Train Thought Experiment as a counterexample to the challenge.

This paper concerns the role of intuitions in mathematics, where intuitions are meant in the Kantian sense, i.e. the “seeing” of mathematical ideas by means of pictures, diagrams, thought experiments, etc.. The main problem discussed here is whether Platonistic argumentation, according to which some pictures can be considered as proofs (or parts of proofs) of some mathematical facts, is convincing and consistent. As a starting point, I discuss James Robert Brown’s recent book Philosophy of Mathematics, in particular, his primarily examples and analogies. I then consider some alternatives and counterarguments, namely John Norton’s opposite view, that intuitions are just pictorially represented logical arguments and are superfluous; and the Kantian transcendental theory of construction in imagination, as it is developed in the works of Marcus Giaquinto and Michael Friedman. Although I support the claim that some intuitions are essential in mathematical justification, I argue that a Platonistic approach to intuitions is partial and one should go further than a Platonist in explaining how some intuitions can deliver new mathematical knowledge.