¹ The Theatetus of Plato. Later reissued with a preface by Cousin, D. R. (University of Glasgow Press, 1977).Google Scholar (Originally published by Jackson, , Wylie and Co.: Glasgow, 1928.)Google Scholar

² London: Macmillan, 1920.

³ Harman, Gilbert, ‘The Inference to the Best Explanation’, Philosophical Review, 74, 88–95CrossRefGoogle Scholar, and Thought (Princeton University Press, 1975).Google Scholar

⁴ Quine, W. V. and Ullian, J. S., The Web of Belief, revised edition (New York: Random House, 1978).Google Scholar

⁵ The term ‘warranted assertability’ apparently goes back to John Dewey, though Dewey did not make the sharp distinction which I hold that we ought to make, between warranted assertability and truth.

⁶ See Thagard, Paul, Computational Philosophy of Science (Cambridge, Mass.: M.I.T. Press, 1988)Google Scholar, and ‘Explanatory Coherence’, Behavioral and Brain Sciences 12 (1989), 435–67.Google Scholar

⁷ See Ellis, Brian, Rational Belief Systems (Oxford: Blackwell, 1979)Google Scholar, Forrest, Peter, The Dynamics of Belief (Oxford: Blackwell, 1986)Google Scholar, Gärdenfors, Peter, Knowledge in Flux: Modeling the Dynamics of Epistemic States (Cambridge, Mass.: M.I.T. Press, 1988).Google Scholar

⁸ Achinstein, Peter, The Nature of Explanation (Oxford: Clarendon Press, 1983).Google Scholar See also Bromberger, Sylvain, ‘An Approach to Explanation’, in Butler, R. J. (ed.), Analytical Philosophy Second Series (Oxford: Basil Blackwell, 1965).Google Scholar

⁹ Rescher, Nicholas in his book The Coherence Theory of Truth (Oxford: Clarendon Press, 1973)Google Scholar, has worked on revising the coherence theory, though I do not agree that it should be seen as a theory of truth.

¹⁰ ‘Explanatory Coherence’, op. cit.

¹¹ Whewell, William, Novum Organon Renovatum (London: John W. Parker, 1858).Google Scholar

¹² As reported in his ‘Explanatory Coherence’, op. cit.

¹³ For earlier work see Thagard, 's Computational Philosophy of Science, op. cit.Google Scholar

¹⁴ This is not of course to decry in any way the efforts of those who have tried (or who do or will try) to precisify these notions. Eminent among them is one of the participants in this conference, Sober, Elliott. In his book Simplicity (Oxford: Clarendon Press, 1975)CrossRefGoogle Scholar Sober defines simplicity as informativeness with respect to a question: a hypothesis is simpler than another to the extent that it requires less extra information for us to answer the question. Sober's approach is syntactic which in effect is to assume that all atomic propositions are equally informative. Thagard, (Computational Philosophy of Science, p. 85)Google Scholar remarks that scientists typically are not concerned about this sort of syntactic simplicity, but regard the number of statements of initial conditions required to supplement a theory to derive an observational statement as irrelevant to the simplicity of a theory. A semantic notion of simplicity seems as fraught with as many difficulties as the notion of subjective probability. But all the same, we need both notions.

¹⁵ Peter Forrest prefers to speak of ‘argument to the best theory’ instead of ‘argument to the best explanation’. I partly agree, but still prefer ‘argument to the best explanation’, because it is the best theory that provides the best explanation, and it is best because it provides the best explanation for the person who wants the explanation. People with different presuppositions, whose puzzles or ‘why?’ questions are different, might require different hypotheses to provide an explanation for them. The hypothesis is not a speech act, but the explanation is, even when it is talking to oneself.

¹⁶ For work on verisimilitude and for references to other recent work on the subject see Oddie, Graham, Likeness to Truth (Dordrecht: D. Reidel, 1986).CrossRefGoogle Scholar The subject is a highly technical and contentious one, and yet if it can be brought to fruition the work on it is surely of the greatest importance for the philosophy of science.

¹⁷ Campbell, N. R., Foundations of Physics (New York: Dover Inc., 1957)Google Scholar, originally published by Cambridge University Press, under the title Physics: The Elements (1920).Google Scholar

¹⁸ Campbell, , Foundations of Physics, 114.Google Scholar

¹⁹ See Strehlow, T. G. H., Aranda Traditions (Melbourne University Press, 1947), 26.Google Scholar

²⁰ Ibid.

²¹ This is one reason why the Laplacean syntactical definition of determinism is better replaced by a model theoretic one.

²² Salmon, Wesley C., Scientific Explanation and the Causal Structure of the World (Princeton University Press, 1984), 47.Google Scholar

²³ Cf. Bromberger, Sylvain, ‘Why-Questions’, in Colodny, Robert G. (ed.), Mind and Cosmos (University of Pittsburgh Press, 1966), 86–111, especially 92.Google Scholar

²⁴ van Fraassen, Bas C., The Scientific Image (Oxford: Clarendon Press, 1980), 132–33.CrossRefGoogle Scholar

²⁵ Philip Kitcher and Wesley Salmon have critically discussed van Fraassen's application of the story in their paper ‘Van Fraassen on Explanation’, Journal of Philosophy (1987), 315–30Google Scholar, especially 317. They think that van Fraassen brings in extraneous considerations. I am inclined to think that the coherence account, for which no considerations need be extraneous, may avoid these criticism.

²⁶ Lewis, David, Counterfactuals (Oxford: Basil Blackwell, 1973).Google Scholar

²⁷ Some of the ways of constructing what Lewis calls ‘ersatz possible worlds’ are essentially metalinguistic. I have not space here to discuss the relevance of ersatz worlds that are supposed to exist in the world of set theory.

²⁸ Salmon, ibid., 170ff.

²⁹ And extended to general relativity by subsequent writers. See Grünbaum, Adolf, Philosophical Problems of Space and Time, 2nd edn (Dordrecht: D Reidel, 1973), 735–50.CrossRefGoogle Scholar For Robb, A. A., see his Geometry of Time and Space (Cambridge University Press, 1936).Google Scholar

³⁰ Adolf Grünbaum used the case of passing clocks in his paper ‘The Clock Paradox in the Special Theory of Relativity’, Philosophy of Science 21 (1954), 249–53Google Scholar and replies to discussions of this, ibid. 22 (1955), 53 and 233.

³¹ I wish to thank Paul Thagard for kindly commenting in correspondence on a draft of this paper, in particular on suggesting corrections to those pages in which I expound his views. He is of course not responsible for defects that remain, and I hope that readers may be encouraged to read his ‘Explanatory Coherence’ and his Computational Philosophy of Science, already cited.