Online research in philosophy

Some very persuasive arguments have been put forward in recent years in support of the disunity of science. Despite this, one is forced to acknowledge that unification, especially the practice of unifying theories, remains a crucial aspect of scientific practice. I explore specific aspects of this tension by examining the nature of theory unification and how it is achieved in the case of the electroweak theory. I claim that because the process of unifying theories is largely dependent on particular kinds of mathematical structures it is possible to have a theory that displays a degree of unity at the level of theoretical structure without an accompanying ontological unity or reduction. As a result, unity and disunity can coexist not only within science but within the same theory.

Abstract The paper addresses the question of how the unity of science can adequately be characterized. A mere classification of scientific fields and disciplines does not express the unity of science unless it is supplemented with a perspective that establishes a systematic coherence among the different branches of science. Four ideas of this kind are discussed. Namely, the unity of scientific language, of scientific laws, of scientific method and of science as a practical?operational enterprise. Whereas reference to the unity of scientific language and of scientific laws does not provide a viable basis for the unity of science, the methodological and practical unity might. The unity of science can be characterized by the way in which methodological criteria enter into the assessment or evaluation of theories, and, moreover, by a transdisciplin?ary approach to problems. Accordingly, the unity of science is not expressed by theoretical uniformity but by the unity of scientific practice.

Several prominent philosophers, including A.J. Ayer and Derek Parfit, have offered the evidentiary requirements for believing human personality can reincarnate, and hence that Cartesian dualism is true. At least one philosopher, Robert Almeder, has argued that there are actual cases which satisfy these requirements. I argue in this paper that even if we grant the empirical data-a large concession-belief in reincarnation is still unjustified. The problem is that without a theoretical account of the alleged cases of reincarnation, the empirical evidence alone does not license giving up materialist theories of the mind.

In this paper a constructive empiricist account of scientific change is put forward. Based on da Costa's and French's partial structures approach, two notions of empirical adequacy are initially advanced (with particular emphasis on the introduction of degrees of empirical adequacy). Using these notions, it is shown how both the informativeness and the empirical adequacy requirements of an empiricist theory of scientific change can then be met. Finally, some philosophical consequences with regard to the role of structures in this context are drawn.Now, we daily see what science is doing for us. This could not be unless it taught us something about reality; the aim of science is not things themselves, as the dogmatists in their simplicity imagine, but the relations between things; outside those relations there is no reality knowable.

In this paper I argue that physics makes metaphysical presuppositions concerning the physical comprehensibility, the dynamic unity, of the universe. I argue that rigour requires that these metaphysical presuppositions be made explicit as an integral part of theoretical knowledge in physics. An account of what it means to assert of a theory that it is unified is developed, which provides the means for partially ordering dynamical physical theories with respect to their degrees of unity. This in turn makes it possible to assess the empirical fruitfulness of (some) metaphysical theses, in terms of the extent to which they play a role in empirically progressive scientific research programmes. A new conception of physics is developed which makes metaphysical theses an integral part of physics and which, at the same time, makes it possible to assess such theses in terms of their empirical fruitfulness. Circularity objections are rebutted.

Theoretical simplicity is difficult to characterize, and evidently can depend upon a number of distinct factors. One such desirable characteristic is that the laws of a theory have relatively few "counterinstances" whose accommodation requires the invocation of a ceteris paribus condition and ancillary explanation. It is argued that, when one theory is reduced to another, such that the laws of the second govern the behavior of the parts of the entities in the domain of the first, there is a characteristic gain in simplicity of the sort mentioned: while I see no way of quantitatively measuring the "amount" of defeasibility of the laws of a theory, microreduction can be shown to decrease that "amount.".

Almost all commentators acknowledge that among the grounds on which scientists perform theory-choices are criteria of simplicity. In general, simplicity is regarded either as only a logico-empirical quality of a theory, diagnostic of the theory's future predictive success, or as a purely aesthetic or otherwise extra-empirical property of it. This paper attempts to demonstrate that the simplicity-criteria applied in scientific practice include both a logico-empirical and a quasi-aesthetic criterion: to conflate these in an account of scientists' theory-choice is to court confusion.

Most scientists and philosophers of science recognize that, when it comes to accepting and rejecting theories in science, considerations that have to do with simplicity, unity, symmetry, elegance, beauty or explanatory power have an important role to play, in addition to empirical considerations. Until recently, however, no one has been able to give a satisfactory account of what simplicity (etc.) is, or how giving preference to simple theories is to be justified. But in the last few years, two different but related accounts have appeared, both of which address the above issues. On the one hand, James McAllister has argued that aesthetic criteria in science reflect scientists' judgements about what kind of theory is most likely to be empirically successful, based on the relative empirical success and failure of different kinds of theories in the past. Scientists employ what McAllister dubs "the aesthetic induction". On the other hand, I have argued that we need to see science as making a hierarchy of metaphysical assumptions about the comprehensibility and knowability of the universe, these assumptions asserting less and less as one ascends the hierarchy. One of the more substantial of these assumptions is that the universe is physically comprehensible. The key non-empirical feature a body of fundamental theories in physics must possess to be acceptable is unity. The better such a body of theory exemplifies the metaphysical thesis that the universe is physically comprehensible, in the sense that it has a unified dynamic structure, so the more acceptable such a body of theory is, from this standpoint. This affects not just theoretical physics, but the whole of natural science. In this paper I compare and contrast, and try to assess impartially the relative merits of, these two views.

There are two problems of simplicity. What does it mean to characterize a scientific theory as simple, unified or explanatory in view of the fact that a simple theory can always be made complex (and vice versa) by a change of terminology? How is preference in science for simple theories to be justified? In this paper I put forward a proposal as to how the first problem is to be solved. The more nearly the totality of fundamental physical theory exemplifies the metaphysical thesis that the universe has a unified dynamic structure, so the simpler that totality of theory is. What matters is content, not form. This proposed solution may appear to be circular, but I argue that it is not. Towards the end of the paper I make a few remarks about the second, justificational problem of simplicity.