Alexander James Bird

Debates concerning the analysis of the concept of law of nature must address the following problem. On the one hand, our grasp of laws of nature is via our knowledge of their instances. And this seems not only an epistemological truth but also a semantic one. The concept of a law of nature must be explicated in terms of the things that instantiate the law. It is not simply that a piece of metal that conducts electricity is evidence for a law that metals conduct electricity. It is also the case that to explicate what it is for there to be such a law requires, and requires little more than, alluding to the fact that the piece of metal conducting electricity is an instance of that law. This is the driving intuition behind regularity theories of laws — to understand the concept ‘law,’ as in ‘it is a law that metals conduct electricity’ one need only understand little more than what it is for something to be a metal and to conduct electricity and the concept of universal generalization. On this view a law just is a regularity (or some kind of regularity) among its instances.

This paper concerns the relationship between dispositions and ceteris paribus laws. Dispositions are related to conditionals. Typically a fragile glass will break if struck with force. But possession of the disposition does not entail the corresponding simple (subjunctive or counterfactual) conditional. The phenomena of finks and antidotes show that an object may possess the disposition without the conditional being true. Finks and antidotes may be thought of as exceptions to the straightforward relation between disposition and conditional. The existence of these phenomena is easy to demonstrate at the macro-Ievel. But do they exist at the fundamental level also? While fundamental finkish dispositions may be excluded fairly straightforwardly, the existence of fundamental antidotes is more open. Nonetheless I conclude that the phenomenon is likely to be less widespread than at the macro level and that fundamental antidotes may be eliminable. According to the dispositional essentialist, the laws of nature can be explained by taking natural properties to be essentially dispositional. This account can be extended to show that the existence of finks and antidotes explains ceteris paribus laws. Consequently the existence or otherwise of fundamental finks and antidotes sheds some light on the question of whether fundamental laws may also be ceteris paribus laws.

Thomas Kuhn was undoubtedly the strongest influence on the philosophy of science in the last third of the twentieth century. Yet today, at the beginning of the twenty-first century it is unclear what his legacy really is. In the philosophy of science there is no characteristically Kuhnian school. This could be because we are all Kuhnians now. But it might also be because Kuhn’s thought, although revolutionary in its time, has since been superseded. In a sense both may be true. We are all Copernicans—yet almost everything Copernicus believed we now disbelieve. In this paper I shall examine the development of Kuhn’s thought in connection with changes in the philosophy of science during the second half of the twentieth century. Now that philosophy in general, philosophy of science in particular, is in a post-positivist era, we all share Kuhn’s rejection of positivism. But we do not, for the most part, share Kuhn’s belief in incommensurability, or his scepticism about truth and objective knowledge. Just as in Copernicus’ case, Kuhn initiated a revolution that went far beyond what he himself envisaged or even properly understood.

1. Contextualism seeks to acknowledge the power of sceptical arguments while permitting to be true at least some of the assertions of knowledge and justification we commonly make. It seems to me now just as if I am in an office in Edinburgh. According to the sceptic the claim that I am in fact in an office in Edinburgh is unjustified, since there is no reason I can give for this belief that is not also consistent with (or undermined by) the alternative hypothesis that I am in fact on a beach in Hawaii being deceived by an evil demon into thinking that I am in an office in Edinburgh. Yet if I were..

In this paper I argue that it is not a priori that all the laws of nature are contingent. I assume that the fundamental laws are contingent and show that some non-trivial, a posteriori, non-basic laws may nonetheless be necessary in the sense of having no counterinstances in any possible world. I consider a law LS (such as 'salt dissolves in water') that concerns a substance S. Kripke's arguments concerning constitution show that the existence of S requires that a certain deeper level law or variants thereof hold. At the same time, that law and its variants may each entail the truth of LS. Thus the existence of S entails LS. Consequently there is no world in which S exists and fails to obey LS. I consider the conditions concerning the fundamental laws that would make this phenomenon ubiquitous. I conclude with some consequences for metaphysics.

The first obstacle that confronts the student of induction is that of defining the subject matter. One initial point is to note that much of the relevant subject matter goes under the description ‘the theory of confirmation’. The distinction is primarily that the study of induction concerns inference, i.e. cases where one takes the conclusion to be established by the evidence, whereas confirmation concerns the weight of evidence, which one may take to be something like the credibility of a hypothesis in the light of the evidence. Discussions of confirmation often concern incremental confirmation, i.e. cases where the evidence is taken to increase the credibility of some hypothesis, even if not sufficiently to warrant inferring the truth of that hypothesis. However, some uses of ‘confirmation’ clearly refer to absolute confirmation, cases where the credibility of the hypothesis in the light of the evidence exceeds some (high) threshold. One may ask whether inductive inference corresponds to the case of absolute confirmation for some suitable threshold. I shall discuss inference and confirmation together, though it should be noted that some approaches eschew inference altogether. For example, the Bayesian takes scientific reasoning to be a matter of adjusting credences in propositions in the light of evidence, and says nothing about unqualified belief in a proposition. However, if we are interested in inductive knowledge then we must consider inference, since only then do we have a detached proposition that is the possible content of a mental state of knowing. A more pressing question concerns which inferences (or allegedly confirmatory relations) should be classed as inductive. A natural and straightforward approach is to define induction as encompassing any form of reasoning that extrapolates from one population to another, usually from a sample of a population to the whole population. For example, one might note that all observations of the position of some planet fall on an ellipse that has the Sun at one of its foci; from this one concludes that all the positions that planet takes fall on this ellipse (i.e..

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.