Logical Pluralism: Where the Conflict Really Lies

Recent years have seen a surge of attention to the problem of logical pluralism; most of which has been a reaction to Beall and Restall’s account of logical pluralism as the existence of more than one equally correct semantic relation of logical consequence. The underlying thesis is that the indeterminacy of the notion of validity goes beyond what the inductive-deductive distinction can precisify. The notion of deductive validity itself is indeterminate as well and this indeterminacy has its roots in the indeterminacy of the more fundamental notion of case. Cases are what make the premisses and the conclusion of an argument true; the most notable example being Tarskian models for classical logic. Deductive validity is the preservation of truth across all cases. This paper argues that unless this account of logical pluralism is supplemented with an argument in favor of the equal legitimacy of the purported cases it becomes merely a semi-controversial exposition of how different logics can be generated

Pluralist Structural Realism: The Best of Both Worlds?

John Worrall (1989) famously claimed that structural realism is the best of both worlds; it enables one to endorse the best arguments for scientific realism and antirealism. In this paper, I argue that structural realism also enables one to combine two other seemingly inconsistent positions: realism and pluralism. Indeed, the very features which form the basis of the structural realist’s reply to the problem of theory change may be applied synchronically to allow for a pluralist structural realism. The resulting position incorporates a robust variety of scientific pluralism unavailable to the traditional realist and thereby allows the structural realist to take seriously the pluralism apparent in scientific practice

Theories, models and structures: thirty years on

Thirty years after the conference that gave rise to The Structure of Scientific Theories, there is renewed interest in the nature of theories and models. However, certain crucial issues from thirty years ago are reprised in current discussions; specifically: whether the diversity of models in the science can be captured by some unitary account; and whether the temporal dimension of scientific practice can be represented by such an account. After reviewing recent developments we suggest that these issues can be accommodated within the partial structures formulation of the semantic or model-theoretic approach

Neo-Carnapian Quietism: A global framework

This thesis explores the highly contested ontological question of what exists, and aims to deflate ontological debates in a quietist fashion, whilst providing an original, positive account of how to proceed by drawing upon ideas from Fictionalism, Meinongianism, and Dialetheism. I follow Rudolf Carnap with respect to the metaontological question of how ontology should be understood and practised, by developing a critique of the traditional realist/antirealist positions and reframing the ontological debate accordingly. Carnap argues that it is not meaningful to question reality in an external sense in order to assess what really exists, rather it is only meaningful to talk in an internal sense within a framework about what exists according to the framework rules. I use the concept of fictions in place of Carnap’s frameworks to argue that we ought to treat much seemingly ontologically committing language as consisting in nothing more than a useful heuristic and as being simply fictional. This reframes ontological debates as being based around the practical advantages of utilizing a way of speaking about existence in a pragmatic fictionalist manner. The aim of my thesis is thus to resurrect Carnap’s metaontology in the form of a unique and global fictionalism, that is divorced from the antirealism usually associated with fictionalism and based on quietism instead. My Neo-Carnapian position is influenced by the Meinongian view of non-existent objects, as I take ontological commitment as distinct from quantificational commitment in order to allow for our quantificational use of language to be ontologically neutral and metaphysically quiet. I further argue that the quietist position results in dialetheism as it finds itself in contradictory realms – in drawing a limit to meaningful metaphysics, it ends up going beyond such limits. My thesis therefore concludes that in redirecting metaphysics towards quietism, metametaphysics is redirected towards dialetheism, in the form of a position I call ‘Neo-Carnapian Quietism’

Spinoza and the Problem of Universals: A Study and Research Guide

This investigatory bibliographic project on Spinoza and the problem of universals draws four principal conclusions. (1) Spinoza is a realist concerning universals. Indeed, Spinoza endorses a radical form of realism known as universalism, the doctrine according to which every ontologically authentic entity is a universal. (2) Spinoza is a realist concerning universal species natures. He holds that a given species nature (such as human nature) is wholly instantiated in each species member. (3) Spinoza combines Aristotelian and Platonic realism. On the one hand, he holds that no universal is ontologically anterior to the one substance God. On the other hand, he holds that all universals with instantiations in the realm of modes are eternal forms ontologically anterior to those instantiations. (4) Spinoza’s pejorative remarks against universals are compatible with his realism. Such remarks are aimed merely at universals apprehendable by sense perception rather than pure intellect

The Natural Ontological Attitude from a Physicist's Perspective: Towards Quantum Realism

The debate between Arthur Fine and Alan Musgrave is well known amongst those involved in the scientific realism debate and centres upon two papers that are quite often found together in philosophy of science anthologies. Reading them like this gives the very strong impression the Musgrave is the victor which is the commonly held view. In this thesis, I wish to overturn this view by placing Fine's paper in context, namely as part of a larger work on the history and philosophy of quantum physics. Fine's book, The Shaky Game: Einstein, Realism and Quantum Theory, gives us good reason to believe that quantum physics significantly undermines the whole scientific realism debate, and as such, has strongly influenced Fine's development of the Natural Ontological Attitude, which is as Fine believes a middle ground between realism and anti-realism. The present thesis evaluates the Natural Ontological Attitude from a physicist's perspective and defends Fine against Musgrave's reply to the extent that it demonstrates that Musgrave would do well to read Fine's paper in context. That said, just as Fine in his youth hoped that a quantum realist position will one day be found, so I also possess this aspiration; and so, despite my concluding that Fine is justified in holding to NOA, I argue furthermore that NOA is but a precursor to a potential quantum structural realist position. After showing that structural realism is worthy of consideration by using it to counter Fine's objections to scientific realism, I analyse the results of quantum physics in an attempt to understand what it can tell us about reality in the quantum realm. Eliminativist Ontic Structural Realism holds great promise as a quantum realism contender, and as such, it inspired the questions regarding individuality and reality that are discussed in the final main chapter. I thus resuscitate hope that the cause of the quantum realist is not yet lost

A fragmented world

Objects often manifest themselves in incompatible ways across perspectives that are on a par. Phenomena of this kind have been responsible for crucial revisions to our conception of the world, both philosophical and scientific. The standard response to them is to deny that the way things appear from different perspectives are ways things really are out there, a response that is based on an implicit metaphysical assumption that the world is a unified whole. This dissertation explores the possibility that this assumption is false, that the world is fragmented instead of unified. On the proposed understanding of such worldly fragmentation, there is a notion of co-obtainment according to which two facts may obtain without co-obtaining. Since not every fact that obtains also co-obtains with every other fact, two incompatible facts may both obtain, as long as they do not co-obtain in the introduced sense. The possibility of such fragmentation sheds new light on a range of phenomena. It allows us to explore a view of time that takes the notion of passage as its defining primitive. It bolsters a no-subject view of experience against the objection that it leads to solipsism. It allows a realist view about colours to withstand the objection from conflicting appearances. And, it makes room for a view on which things really have the properties that are attributed to objects and events across different frames of reference, such as length, mass, duration and simultaneity. Overall, fragmentalism changes the way in which the manifest image feeds into an objective conception of the world: what is manifest to us is not misleading in what sort of properties it shows the world to have, it's only misleading in making it seem more unified than it really is

Epistemic Characterizations of Validity and Level-Bridging Principles

How should we understand validity? A standard way to characterize validity is in terms of the preservation of truth (or truth in a model). But there are several problems facing such characterizations. An alternative approach is to characterize validity epistemically, for instance in terms of the preservation of an epistemic status. In this paper, I raise a problem for such views. First, I argue that if the relevant epistemic status is factive, such as being in a position to know or having conclusive evidence for, then the account runs into trouble if we endorse certain familiar logical principles. Second, I argue that if the relevant epistemic status is non-factive, such as is rationally committed to or has justification for believing, then a similar problem arises if we endorse the logical principles as well as a sufficiently strong epistemic "level-bridging" principle. Finally, I argue that an analogous problem arises for the most natural characterization of validity in terms of rational credence