Alexander James Bird

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..

Is the nature of explanation a metaphysical issue? Or has it more to do with psychology and pragmatics? To put things in a different way: what are primary relata in an explanation? What sorts of thing explain what other sorts of thing? David Lewis identifies two senses of ‘explanation’ (Lewis 1986, 217–218). In the first sense, an explanation is an act of explaining. I shall call this the subjectivist sense, since its existence depends on some subject doing the explaining. Hence it is people who, in this sense, explain things. In the second of his two senses, Lewis says, quoting Sylvain Bromberger, that one may properly ask of an explanation “Does anyone know it? Who thought of it first? Is it very complicated?” (Lewis 1986, 218; Bromberger 1965). In this second sense, no subject is needed, the explanation can remain unknown, perhaps for ever. So I call this the objectivist sense.

Emergent properties are intended to be genuine, natural higher level causally efficacious properties irreducible to physical ones. At the same time they are somehow dependent on or 'emergent from' complexes of physical properties, so that the doctrine of emergent properties is not supposed to be returned to dualism. The doctrine faces two challenges: (i) to explain precisely how it is that such properties emerge - what is emergence; (ii) to explain how they sidestep the exclusion problem - how it is that there is room for these properties to be causally efficacious, given the causal completeness of the physical. In this paper I explain how functional properties can meet both challenges.

In his (2002) Gonzalo Rodriguez-Pereyra provides a powerful articulation of the claim that Resemblance Nominalism provides the best answer to the so-called Problem of Universals. Resemblance Nominalism has not been popular for some time, and one influential reason for this is the widespread belief that Resemblance Nominalism cannot dispense with all universals. The realist critics appeal to what is known as Russell’s Regress (cf. Russell 1997). If properties are to be explained in terms of one object’s resembling another, then this seems to leave the relational property of resemblance itself unexplained. The critics’ objection is that this property itself must be explained by a dyadic universal of resemblance.

I show that Armstrong’s view of laws as second-order contingent relations of ‘necessitation’ among categorical properties faces a dilemma. The necessitation relation confers a relation of extensional inclusion (‘constant conjunction’) on its relata. It does so either necessarily or contingently. If necessarily, it is not a categorical relation (in the relevant sense). If contingently, then an explanation is required of how it confers extensional inclusion. That explanation will need to appeal to a third-order relation between necessitation and extensional inclusion. The same dilemma reappears at this level. Either Armstrong must concede that some properties are not categorical but have essential powers – or he is faced with a regress.

Let us call a property that is essentially dispositional a potency.1 David Armstrong thinks that potencies do not exist. All sparse properties are essentially categorical, where sparse properties are the explanatory properties of the type science seeks to discover. An alternative view, but not the only one, is that all sparse properties are potencies or supervene upon them. In this paper I shall consider the differences between these views, in particular the objections Armstrong raises against potencies.

In this article I take a loose, functional approach to defining induction: Inductive forms of reasoning include those prima facie reasonable inference patterns that one finds in science and elsewhere that are not clearly deductive. Inductive inference is often taken to be reasoning from the observed to the unobserved. But that is incorrect, since the premises of inductive inferences may themselves be the results of prior inductions. A broader conception of inductive inference regards any ampliative inference as inductive, where an ampliative inference is one where the conclusion ‘goes beyond’ the premises. ‘Goes beyond’ may mean (i) ‘not deducible from’ or (ii) ‘not entailed by’. Both of these are problematic. Regarding (i), some forms of reasoning might have a claim to be called ‘inductive’ because of their role in science, yet turn out to be deductive after all—for example eliminative induction (see below) or Aristotle’s ‘perfect induction’ which is an inference to a generalization from knowledge of every one of its instances. Interpretation (ii) requires that the conclusions of scientific reasoning are always contingent propositions, since necessary propositions are entailed by any premises. But there are good reasons from metaphysics for thinking that many general propositions of scientific interest and known by inductive inference (e.g. “all water is H2O”) are necessarily true. Finally, both (i) and (ii) fail to take account of the fact that there are many ampliative forms of inference one would not want to call inductive, such as counter-induction (exemplified by the ‘gambler’s fallacy’ that the longer a roulette wheel has come up red the more likely it is to come up black on the next roll). Brian Skyrms (1999) provides a useful survey of the issues involved in defining what is meant by ‘inductive argument’. Inductive knowledge will be the outcome of a successful inductive inference. But much discussion of induction concerns the theory of confirmation, which seeks to answer the question, “when and to what degree does evidence support an hypothesis?” Usually, this is understood in an incremental sense and in a way that relates to the rational credibility of a hypothesis: “when and by how much does e add to the credibility of h?”, although ‘confirms’ is sometimes used in an absolute sense to indicate total support that exceeds some suitably high threshold..

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.

La thèse kuhnienne de l’incommensurabilité semble mettre en cause le réalisme scientifique. Une réponse à cette mise en cause consiste à se focaliser sur la continuité de la référence. La théorie causale de la référence, en particulier, semble offrir la possibilité d’une continuité de la référence susceptible de fournir une base pour l’espèce de comparabilité entre théories que requiert le réaliste. Dans « baptiser et rebaptiser : la vulnérabilité des désignations rigides », Kuhn attaque la théorie causale et l’essentialisme auquel cette théorie est liée. La position de Kuhn est défendue par Rupert Read et Wes Sharrok [Read & Sharrok 2002b]. Dans cet article, j’examine les arguments présentés par Kuhn, Read et Sharrok, et je montre qu’ils ne fournissent aucune raison de douter ni de la théorie causale, ni de l’essentialisme.