Classifying is a fundamental operation in the acquisition of knowledge. Taxonomic theory can help students of cognition, evolutionary psychology, ethology, anatomy, and sociobiology to avoid serious mistakes, both practical and theoretical. More positively, it helps in generating hypotheses useful to a wide range of disciplines. Composite wholes, such as species and societies, are “individuals” in the logical sense, and should not be treated as if they were classes. A group of analogous features is a natural kind, but a group of (...) homologous features is not. Imposing hypotheses justified only on the basis of nominalist, realist, phenomenalist, or conceptualist metaphysics upon the neurophysiology of organisms or upon the causes of behavior exemplifies the “psychologist's fallacy” of William James. Levels should be distinguished from their members and from classes of levels, and the ontological status of entities ranked at levels should be made clear. It is important not to confuse such categories as substance and process with one another. Several genetical terms, such as “gene” and chromosome,” are even more equivocal than has been realized. Discussions about units of selection, behavior, and thinking suffer from the ambiguity of a “unit of” an entity. An important source of misunderstanding about natural selection is the habit of treating it as an “agent”: in an important sense, natural selection does not “act” at all. (shrink)

This essay examines some of the arguments in David Deutsch's book The Fabric of Reality , chief among them its case for the so-called many-universe interpretation of quantum mechanics (QM), presented as the only physically and logically consistent solution to the QM paradoxes of wave/particle dualism, remote simultaneous interaction, the observer-induced 'collapse of the wave-packet', etc. The hypothesis assumes that all possible outcomes are realized in every such momentary 'collapse', since the observer splits off into so many parallel, coexisting, but (...) epistemically non-interaccessible 'worlds' whose subsequent branchings constitute the lifeline-or experiential world-series- for each of those proliferating centres of consciousness. Although Deutsch concedes that his 'multiverse' theory is counter-intuitive, he none the less takes it to be borne out beyond question by the sheer observational/predictive success of QM and the conceptual dilemmas that supposedly arise with alternative (single-universe) accounts. Moreover, he claims the theory resolves a range of longstanding philosophical problems, notably those of mind/body dualism, the various traditional paradoxes of time, and the freewill/determinism issue. The essay suggests on the contrary, that Deutsch unwittingly transposes into the framework of presentday quantum debate speculative themes from the history of rationalist metaphysics, often with bizarre or philosophically dubious results, and that he rules out at least one promising rival account, namely Bohm's 'hidden variables' theory. It goes on to consider reasons for resistance to that theory among proponents of the 'orthodox' (Copenhagen) doctrine, and for the strong anti-realist, at times even irrationalist bias that has characterized much of this discussion since Bohr's debates with Einstein about quantum non-locality, observer-intervention, and the limits of precise measurement. Finally, the contrast is pointed out between Deutsch's ontologically extravagant use of the many-worlds hypothesis (akin to certain ideas advanced by speculative metaphysicians from Leibniz down) and those realist modes of counterfactual reasoning- e.g. in Kripke and the early Putnam- which deploy similar arguments to very different causal-explanatory ends. (shrink)

In Fictional Discourse, I proposed an analysis of what I call ‘fictional discourse’, first and foremost as it appears in an author’s fictional creation (what Ta.

In the first part ("Determination"), I consider different notions of determination, contrast and compare modal with non-modal accounts and then defend two a-modality theses concerning essence and supervenience. I argue, first, that essence is a a-modal notion, i.e. not usefully analysed in terms of metaphysical modality, and then, contra Kit Fine, that essential properties can be exemplified contingently. I argue, second, that supervenience is also an a-modal notion, and that it should be analysed in terms of constitution relations between properties. (...) In the second part ("A Theory of Truthmaking"), I first review the literature on ontological commitment, and argue that the notion of truthmaking is better suited to play its explanatory rôle. I then argue that we should take truthmaker theory seriously, and that we should provide actual truthmakers for all truths there are. In the last chapter of this part, I review Armstrong's truthmaker theories and argue that they are unsatisfactory. I generalise my criticism to an argument against truthmaker necessitarianism, the view that truthmakers necessarily make true the truths they are truthmakers of. In the third part ("Properties and their Kind(s)"), I discuss qualitative determination. I present and endorse the truthmaker argument for universals, and defend universalism against friends of tropes, states of affairs and facts. I then give a novel characterisation of the important class of intrinsic properties, building on Lewis' work. With a workable notion of intrinsicness at hand, I argue that relations are ontologically – but not "ideologically" – dispensable: qualitative determination in general is a matter of intrinsic structure. In the future, I plan to add two parts and to publish my thesis as a book: In the fourth part ("Exemplification"), I argue for the existence of an exemplification relation tying universals and particulars together. I derive theoretical benefits from this relation by providing adverbialist theories of modality and tense and identify exemplification with a type of parthood. In the fifth part ("Qua qua qua"), I investigate the curious and interesting ontological category of so-called "qua-objects" (Picasso-as-a-painter, for example) and argue that they exist, are not identical with transworld indidivuals or modal parts and that they provide (contingent) truthmakers for all true predications. (shrink)

Theoria, Volume 88, Issue 2, Page 453-463, April 2022.

In the Essay Locke argues abstract ideas within the framework of the descriptivist theory of reference. For him, abstract ideas are, in many cases, conceptual ideas that play the role of “descriptions” or “descriptive contents,” determining general terms’ referents. In contrast, in the introduction of the Principles, Berkeley denies Lockean abstract ideas adamantly from an imagistic point of view, and he offers his own theory of reference seemingly consisting of referring expressions and their referents alone. However, interestingly, he mentions a (...) general term’s “definition” and suggests that it determines the scope of the term’s referents. For example, he takes up the definition of a triangle as “a plain Surface comprehended by three right Lines” and suggests that just as Locke’s general idea of a triangle does, the definition determines the referents of the general term “triangle.” His definition reminds us of the fact that as Descartes grasps the content of the general idea of a triangle as “a figure enclosed by three lines,” so Locke grasps the abstract idea of a triangle as “a Figure including a Space between three Lines,” and so on. That is, since Berkeley is an imagist, he does not acknowledge Locke’s conceptual abstract ideas as “ideas,” but although he verbally denies “abstract ideas,” his theory of reference also actually has the same descriptivist framework consisting of referring expressions, their descriptive contents, and their referents. Thus, we understand the real reason why Berkeley’s criticism of Locke seems beside the point. (shrink)

Richard Rorty is easily cast as the intellectual godfather of our post-truth condition. But unlike Nicholas Gaskill, whose article in Common Knowledge 28, no. 3, has engendered a continuing symposium in the journal, Professor Fuller sees Rorty's role as being to his credit rather than detriment. Rorty extended W. B. Gallie's idea of “essentially contested concepts” from the moral and political spheres to the epistemic, thereby rendering such terms as truth, reason, and evidence inherently vague, which means that they are (...) defined not a priori but only in the context of exemplary concrete cases. Doing so invariably results in a “redescription” of what is observed that explains the “meta” level of understanding that philosophy brings to whatever it discusses. In this sense, all that the post-truth condition does is turn everyone into a philosopher. (shrink)

The tradition of semantic externalism that follows Kripke and Putnam is built on the assumption that the folk have essentialist commitments about natural kinds. Externalists commonly take the body of empirical data concerning psychological essentialism as support for this claim. However, recent empirical findings call the psychological theory of essentialism into question. This thesis examines the relevance of these findings to both essentialism and semantic externalism. I argue that these findings suggest that these theories fail to reflect folk beliefs about (...) natural kinds and folk natural kind term usage. This leads me to propose an alternative thesis-- the Ambiguity Thesis-- that is better able to accommodate the existing body of empirical data. (shrink)

This article examines Hilary Putnam's work in the philosophy of mathematics and - more specifically - his arguments against mathematical realism or objectivism. These include a wide range of considerations, from Gödel's incompleteness-theorem and the limits of axiomatic set-theory as formalised in the Löwenheim-Skolem proof to Wittgenstein's sceptical thoughts about rule-following, Michael Dummett's anti-realist philosophy of mathematics, and certain problems – as Putnam sees them – with the conceptual foundations of Peano arithmetic. He also adopts a thought-experimental approach – a (...) variant of Descartes' dream scenario – in order to establish the in-principle possibility that we might be deceived by the apparent self-evidence of basic arithmetical truths or that it might be ‘rational’ to doubt them under some conceivable set of circumstances. Thus Putnam assumes that mathematical realism involves a self-contradictory ‘Platonist’ idea of our somehow having quasi-perceptual epistemic ‘contact’ with truths that in their very nature transcend the utmost reach of human cognitive grasp. On this account, quite simply, ‘nothing works’ in philosophy of mathematics since wecan either cling to that unworkable notion of objective truth or abandon mathematical realism in favour of a verificationist approach that restricts the range of admissible statements to those for which we happen to possess some means of proof or ascertainment. My essay puts the case, conversely, that these hyperbolic doubts are not forced upon us but result from a false understanding of mathematical realism – a curious mixture of idealist and empiricist themes – which effectively skews the debate toward a preordained sceptical conclusion. I then go on to mount a defence of mathematical realism with reference to recent work in this field and also to indicate some problems – as I seethem – with Putnam's thought-experimental approach as well ashis use of anti-realist arguments from Dummett, Kripke, Wittgenstein, and others. (shrink)

The terminology of ‘essence’ and ‘accident’, which it is customary to trace back to Aristotle, has been given a new lease of life by recent writing on logic and metaphysics. Aristotle's notion of ‘essence’ is notoriously difficult and obscure, but the works of Putnam 1 on natural kinds, Kripke 2 on naming and Wiggins 3 on identity may be seen as providing a new rationale, with a distinctive scientific twist, for talk of essences. This revival in the fortunes of essentialism (...) merits closer examination, for whilst it may be that modern versions of essentialism have avoided some of the difficulties of Aristotle's account, they have imported others which may prove no less intractable. (shrink)