Alexander James Bird

Frege's logicism consists of two theses: the truths of arithmetic are truths of logic; the natural numbers are objects. In this paper I pose the question: what conception of logic is required to defend these theses? I hold that there exists an appropriate and natural conception of logic in virtue of which Hume's principle is a logical truth. Hume's principle, which states that the number of Fs is the number of Gs iff the concepts F and G are equinumerous is the central plank in the neo-logicist argument for and. I defend this position against two objections Hume's principle canot be both a logical truth as required by and also have the ontological import required by ; and the use of Hume's principle by the logicist is in effect an ontological proof of a kind which is not valid.

Peter Lipton argues that inference to the best explanation involves the selection of a hypothesis on the basis of its loveliness. I argue that in optimal cases of IBE we may be able to eliminate all but one of the hypotheses. In such cases we have a form of eliminative induction takes place, which I call ‘Holmesian inference’. I argue that Lipton’s example in which Ignaz Semmelweis identified a cause of puerperal fever better illustrates Holmesian inference than Liptonian IBE. I consider in detail the conditions under which Holmesian inference is possible and conclude by considering the epistemological relations between Holmesian inference and Liptonian IBE.Keywords: Inference to the best explanation; Peter Lipton; Abduction; Holmesian inference; Eliminative induction.

This paper sketches a dispositionalist conception of laws and shows how the dispositionalist should respond to certain objections. The view that properties are essentially dispositional is able to provide an account of laws that avoids the problems that face the two views of laws (the regularity and the contingent nomic necessitation views) that regard properties as categorical and laws as contingent. I discuss and reject the objections that (i) this view makes laws necessary whereas they are contingent; (ii) this view cannot account for certain kinds of laws of nature and their properties.

I defend against criticism the following claims concening Thomas Kuhn: (i) there is a strong naturalist streak in The structure of scientific revolutions, whereby Kuhn used the results of a posteriori enquiry in addressing philosophical questions; (ii) as Kuhn's career as a philosopher of science developed he tended to drop the naturalistic elements and to replace them with more traditionally philosophical a prior approaches; (iii) at the same there is a significant residue of positivist thought in Kuhm, which Kuhn did not recognise as such; (iv) the naturalist elements referred to in (i) are the most original and fruitful elements of Kuhn's thinking; (v) the positivistic elements referred to in (iii) vitiated his thought and acted as factors in preventing Kuhn from developing the naturalistic elemtns and from following the path taken by much subsequent philosophy of science. Preston presents an alternative reading of Kuhn which emphasizes the Wittgensteinian elements in Kuhn. I argue that this alternative view is, descriptively, poorly supported by the textual evidence and the facts of the history of philosophy of science in the twentieth century. I provide some defence of the naturalistic approach and related themes.

Dispositional essentialism, a plausible view about the natures of (sparse or natural) properties, yields a satisfying explanation of the nature of laws also. The resulting necessitarian conception of laws comes in a weaker version, which allows differences between possible worlds as regards which laws hold in those worlds and a stronger version that does not. The main aim of this paper is to articulate what is involved in accepting the stronger version, most especially the consequence that all possible properties exist in all worlds. I also suggest that there is no particularly strong reason for preferring the weaker to the stronger version. For example, Armstrong's instantiation condition on universals entails that according to strong necessitarianism every property is instantiated in all possible worlds. But first we do not need to accept Armstrong's instantiation condition, in part because his arguments for it are forceful only for a contingentist about laws and properties. Secondly, even if we do accept the condition, the consequence that all properties are instantiated is not itself contradictory, so long as any form of necessitarianism holds. Strong necessitarianism is prima facie counter-intuitive. But for that matter so is weak necessitarianism. Accepting either weak or strong necessitarianism requires denying the force of intuition in this area. And indeed we have every reason to deny the force of intuition and its primary source, imagination, concerning modal facts.

In my 'Dispositions and Antidotes', The Philosophical Quarterly, 48 (1998), I raise an objection to the conditional analysis of dispositions, both in its simple formulation and in a more sophisticated version due to David Lewis, The Philosophical Quarterly, 47 (1997). The objection suggests that a disposition may be continuously present and the appropriate stimulus occur without the manifestation occurring, because some outside influence, an antidote, interferes. Gundersen in The Philosophical Quarterly, 50 (2000), argues that my objection rests on an equivocation about which object possesses the disposition and more particularly on an equivocation about the context in which the events referred to take place, and that when the equivocation is resolved the counter-example disappears. I respond by showing that the counter-example does remain if we take contextual and mereological issues into account, and I conclude by remarking that the difference with Lewisdepends on whether certain features are seen as significant for the semanticsand metaphysics of dispositions or as merely characteristic of the pragmaticsof common usage.

Many introductions to this field start with the problem of justifying scientific knowledge but Alexander Bird begins by examining the subject matter, or metaphysics, of science. Using topical scientific debates he vividly elucidates what it is for the world to be governed by laws of nature. This idea provides the basis for explanations and causes and leads to a discussion of natural kinds and theoretical entities. With this foundation in place he goes on to consider the epistemological issues of how science arrives at knowledge, favouring a treatment of scientific reasoning based on inference to the best explanation. Drawing on contemporary work in epistemology, Bird argues that scepticism about induction should not be a problem for science and examines the consequences of this position for controversies surrounding the ideas of scientific progress and scientific revolution. Bird's insightful treatment makes Philosophy of Science an ideal text for undergraduate courses. The guides to further reading provided in each chapter help the reader pursue interesting topics and facilitate the use of the book in conjunction with primary sources.

Dispositional monism is the view that natural properties and relations are ‘pure powers’. It is objected that dispositional monism involves some kind of vicious or otherwise unpalatable regress or circularity. I examine ways of making this objection precise. The most pressing interpretation is that is fails to make the identities of powers determinate. I demonstrate that this objection is in error. It does however puts certain constraints on what the structure of fundamental properties is like. I show what a satisfactory structure would be.