Online research in philosophy

The concern with the objectivity of observations is as old as empirical study itself. Protagoras’ assertion that ‘Man is the measure of all things’, though not particularly directed at observations, raised general doubts concerning the objectivity of our beliefs. In the twentieth century, the concern has been brought under the banner ‘theory-ladenness of observation’. In simple terms, since observations are conducted and formulated in theory-specific contexts, they are inadvertently imbued with the prejudices of those contexts - the terms ‘theory’ and ‘observation’ are here broadly construed. Accordingly, it is argued, observations cannot be neutral in the testing of theories.

In a 2008 paper, Walmsley argued that the explanations employed in the dynamical approach to cognitive science, as exemplified by the Haken, Kelso and Bunz model of rhythmic finger movement, and the model of infant preservative reaching developed by Esther Thelen and her colleagues, conform to Carl Hempel and Paul Oppenheim’s deductive-nomological model of explanation (also known as the covering law model). Although we think Walmsley’s approach is methodologically sound in that it starts with an analysis of scientific practice rather than a general philosophical framework, we nevertheless feel that there are two problems with his paper. First, he focuses only on the deductivenomological model and so neglects the important fact that explanations are causal. Second, the explanations offered by the dynamical approach do not take the deductive-nomological format, because they do not deduce the explananda from exceptionless laws. Because of these two points, Walmsley makes the dynamical explanations in cognitive science appear problematic, while in fact they are not.

Towards the middle of the eighteenth century Hume asked: Why should we accept non-deductive inferences? Strangely enough he didn’t ask the corresponding question: Why should we accept deductive inferences? This was not due to an oversight but rather to the belief, widespread even today, that there is a basic difference between deductive and non-deductive inferences: while non-deductive inferences cannot be justified, deductive inferences can be justified. Though widespread even today, such belief has been challenged by a number of people, from Sextus Empiricus to Lewis Carroll. However, although their arguments raise doubts about the possibility of justifying deductive inferences, many people still believe that, while non-deductive inferences cannot be justified, deductive inferences can be justified. The question of the justification of deductive inferences is all the more important as it is strictly connected with the question: What is a deductive inference? and a non-deductive inference? This paper provides a new answer to these questions.

The striking difference between the orthodox nomological necessitation view of laws and the claims made recently by Scientific Essentialism is that on the latter interpretation laws are metaphysically necessary while they are contingent on the basis of the former. This shift is usually perceived as an upgrading: essentialism makes the laws as robust as possible. The aim of my paper—in which I contrast Brian Ellis’s Scientific Essentialism and David Armstrong’s theory of nomological necessity—is threefold. (1) I first underline the familiar fact that metaphysical necessity (of Kripkean “water is necessarily H2O” kind) is not a stronger kind of necessity than nomological necessity but an entirely different kind of thing: nomological, but not metaphysical necessity, is an intra-world necessitation which Armstrong (almost) identifies with causation; metaphysical, but not nomological necessitation, has a canonical link to possible world considerations and counterfactual reasoning. Hence, the change from one necessity to the other is not an upgrading but a substantial shift. (2) I will explain how the essentialists, who promote this shift, are nonetheless able to retain the features of nomological necessity. (3) I also explore, for both the essentialist and the Armstrongian, whether they could extract a modal force from intra-world nomological necessity which it does not have per se. I argue that such a modal force is, indeed, obtainable for them. I will close the paper with some remarks and questions about the relation between Kripkean metaphysical necessity and the modal version of nomological necessity as defined in (3).

The view that scientific theories are partially interpreted deductive systems (theoretical deductivism) is defended against recent criticisms by Hempel. Hempel argues that the reliance of theoretical inferences (both from observation to theory and also from theory to theory) uponceteris paribus conditions orprovisos must prevent theories from establishing deductive connections among observations. In reply I argue, first, that theoretical deductivism does not in fact require the establishing of such deductive connections: I offer alternative H-D analyses of these inferences. Second, I argue that when the refined character of scientific observation is taken into account, we find that a theorymay after all establish such deductive connections among scientific observations, without reliance on provisos.These conclusions are based on the multi-level Popperian contextualist account of empirical interpretation sketched in a previous paper. As before, I claim that the supposed objections to theoretical deductivism depend upon questionable empiricist theses unnecessarily conjoined with theoretical deductivism by the Logical Positivists. Theoretical deductivism itself is unaffected by these arguments, and remains (when empirical interpretation is properly analyzed) the best account of scientific theories.

It has been the dominant view that probabilistic explanations of particular facts must be inductive in character. I argue here that this view is mistaken, and that the aim of probabilistic explanation is not to demonstrate that the explanandum fact was nomically expectable, but to give an account of the chance mechanism(s) responsible for it. To this end, a deductive-nomological model of probabilistic explanation is developed and defended. Such a model has application only when the probabilities occurring in covering laws can be interpreted as measures of objective chance, expressing the strength of physical propensities. Unlike inductive models of probabilistic explanation, this deductive model stands in no need of troublesome requirements of maximal specificity or epistemic relativization.

We revive the idea that a deductive-nomological explanation of a scientific theory by its successor may be defensible, even in those common and troublesome cases where the theories concerned are mutually incompatible; and limiting, approximating and counterfactual assumptions may be required in order to define a logical relation between them. Our solution is based on a general characterization of limiting relations between physical theories using the method of nonstandard analysis.

Variational evolutionary theory as advocated by Darwin is not a single theory, but a bundle of related but independent theories, namely: (a) variational evolution; (b) gradualism rather than large leaps; (c) processes of phyletic evolution and of speciation; (d) causes for the formation of varying individuals in populations and for the action of selective agents; and (e) all organisms evolved from a common ancestor. The first four are nomological-deductive explanations and the fifth is historical-narrative. Therefore evolutionary theory must be divided into nomological and historical theories which are both testable against objective empirical observations. To be scientific, historical evolutionary theories must be based on well corroborated nomological theories, both evolutionary and functional. Nomological and general historical evolutionary theories are well tested and must be considered as strongly corroborated scientific theories. Opponents of evolutionary theory are concerned only with historical evolutionary theories, having little interest in nomological theory. Yet given a well corroborated nomological evolutionary theory, historical evolutionary theories follow automatically. If understood correctly, both forms of evolutionary theories stand on their own as corroborated scientific theories and should not be labeled as facts.