Ethan Lowe

The aim of the paper is to prove the consistency of libertarianism. We examine the example of Jane, who deliberates at length over whether to vacation in Colorado (C) or Hawaii (H), weighing the costs and benefits, consulting travel brochures, etc. Underlying phenomenological deliberation is an indeterministic neural process in which nonactual motor neural states n(C) and n(H) corresponding to alternatives C and H remain physically possible up until the moment of decision. The neurophysiological probabilities pr(n(C)) and pr(n(H)) evolve continuously according to the different weights Jane's judgement attaches to C and H at different times during the deliberation. The overall process is indeterministic, since Jane's exact judgemental weighting would vary slightly were the process to be repeated from the same initial conditions. The weighting is however rational, and entirely under Jane's control. This controlled, rational, indeterministic process shows that libertarianism is a consistent philosophical thesis.

The thesis of 3D/4D equivalence states that every three-dimensional description of the world is translatable without remainder into a four-dimensional description, and vice versa. In representing an object in 3D or in 4D terms we are giving alternative descriptions of one and the same thing, and debates over whether the ontology of the physical world is "really" 3D or 4D are pointless. The twins paradox is shown to rest, in relativistic 4D geometry, on a reversed law of triangle inequality. But considering the twins as 3D beings who age through time, the paradox implies that time passes at different rates in different reference frames, and therefore that the concept of a single global or Absolute time is unsustainable

In the Second Meditation, Descartes famously asks at one point, ‘But what then am I?’ – to which his immediate answer is ‘A thing that thinks.’ It is this question, or rather the plural version of it, that Eric Olson examines in this excellent book. He thinks that it is – today, at least – a rather neglected question. He points out that it is wrong to confuse the question with the much more frequently examined question of what personal identity consists in. In fact, he thinks that possible answers to the two questions, even if not entirely independent of one other, constrain each other only to a rather limited extent. It is important to appreciate that Olson is not inquiring into what persons in general are, but only into what we human persons are. Olson explores all the major, and some of the less well-known, answers that have been offered to this question. He begins with the answer that he himself has defended in an earlier book, The Human Animal – the answer that we are human animals, that is, biological organisms of a certain kind. Indeed, Olson is, along with Peter van Inwagen, one of the best known ‘animalists’ – although he admits to being a little more tentative in his endorsement of this position now, for reasons that we shall come to later. The other views that he considers are these: that we are entities that are ‘constituted’ by, but not identical with, human animals (the view of Lynne Rudder …

'Object' and 'criterion of identity' are philosophical terms of art whose application lies at a considerable theoretical remove from the surface phenomena of everyday linguistic usage. This partly explains their highly controversial status, for their point of application lies precisely where the concerns of linguists and philosophers of language merge with those of metaphysicians. This chapter explains the possession of determinate identity‐conditions. It argues that the distinction between 'abstract' and 'concrete' objects is itself a highly controversial one, and although it has indeed been argued that this distinction turns ultimately upon differences between the criteria of identity governing objects of these two broad categories. It examines the role which criteria of identity play in our talk about objects of the least controversial varieties. The chapter concerns the problem of identity over time and the paradoxes to which identity criteria often appear to give rise when time is brought into the picture.

Eric T. Olson has argued that those who hold that two material objects can exactly coincide at a moment of time, with one of these objects constituting the other, face an insuperable difficulty in accounting for the alleged differences between the objects, such as their being of different kinds and possessing different persistence-conditions. The differences, he suggests, are inexplicable, given that the objects in question are composed of the same particles related in precisely the same way. In response, I show that the differences are not at all inexplicable once it is recognized that the conditions for a persisting object to be composed by certain particles at a moment of time must involve facts concerning other moments of time, and that the relevant facts are different for persisting objects of different kinds. Philosophers who neglect this sort of constraint on composition principles may be said to be victims of the 'cinematographic fallacy'

I propose a fourfold categorisation of entities according to whether or not they possess determinate identity-conditions and whether or not they are determinately countable. Some entities – which I call ‘individual objects’ – have both determinate identity and determinate countability: for example, persons and animals. In the case of entities of a kind K belonging to this category, we are in principle always entitled to expect there to be determinate answers to such questions as ‘Is x the same K as y?’ and ’How many Ks are there satisfying condition C?’, even if we may sometimes be unable in practice to discover what these answers are. But other entities apparently lack either determinate identity, or determinate countability, or both. In these terms I try to explain certain important ontological differences between familiar macroscopic objects and various rather more esoteric entities, such as the ‘particles’ of quantum physics, quantities of material stuff, and tropes or property instances.

David Lewis, following in the tradition of Broad, Quine and Goodman, says that change in an object X consists in X's being temporally extended and having qualitatively different temporal parts. Analogously, change in a spatially extended object such as a road consists in its having different spatial parts . The alternative to this view is that ordinary objects undergo temporal change in virtue of having different intrinsic non-relational properties at different times. They endure, remaining the same object throughout change, whereas Lewis's temporally extended 4D objects perdure.It is impossible to come down on one side or the other of the endurance/perdurance debate without a clear and unambiguous understanding of what ‘endurance’ is. ‘Perdurance’ is clear enough. Every 4D object of non-zero temporal thickness perdures simply by having temporal extension, i.e. by having different temporal parts, or stages, at different times. But Lewis muddies the waters by giving a confused and ultimately untenable definition of endurance.His first step is to cover both perduring and enduring by offering the neutral word persist. ‘Let us say that something persists iff, somehow or other, it exists at various times’ . Something then perdures if it persists by having different temporal parts at different times, no one part being wholly present at more than one time. In contrast, a thing endures if it persists by being wholly present at more than one …

Substantial change occurs when a persisting object of some kind either begins or ceases to exist. Typically, this happens when one or more persisting objects of another kind or kinds are subjected to appropriate varieties of qualitative or relational change, as when the particles composing a lump of bronze are rearranged so as to create a statue. However, such transformations also seem to result, very often, in cases of spatiotemporal coincidence, in which two numerically distinct objects of different kinds exist in exactly the same place at the same time, such as a statue and a lump of bronze. Various attempts to resist this way of describing the results of such transformations are examined and found wanting and objections to the possibility of cases of spatiotemporal coincidence are rebutted

Ontological dependence is a relation—or, more accurately, a family of relations—between entities or beings. For there are various ways in which one being may be said to depend upon one or more other beings, in a sense of “depend” that is distinctly metaphysical in character and that may be contrasted, thus, with various causal senses of this word. More specifically, a being may be said to depend, in such a sense, upon one or more other beings for its existence or for its identity. Some varieties of ontological dependence may be analyzed in modal terms—that is, in terms of distinctly metaphysical notions of possibility and necessity—while others seem to demand an analysis in terms of the notion of essence. The latter varieties of ontological dependence may accordingly be called species of essential dependence. Notions of ontological dependence are frequently called upon by metaphysicians in their proposed analyses of other metaphysically important notions, such as the notion of substance

Patrick Grim, The incomplete universe:totality, knowledge, and truth. Cambridge, Mass, and London: The MIT Press, 1991. xiv + 165pp. £22.50 Jan SebestikLogique et mathématique chez Bernard Bolzano. Paris:Vrin, 1992. 522 pp. 198Fr J. De Lorenzo, Kant y la matemâtica. El uso constructivo de la razön pura Madrid:Editorial Tecnos, 1992. 180 pp. No price stated F. Coniglione, R. Poli And J. Woleintski, Polish scientific philosophy:The Lvov-Warsaw school. Amsterdam and Atlanta, Georgia: Rodopi, 1993. xi + 358pp. No price stated I. Kant Lectures on logic. Translated and edited by J. Michael Young. Cambridge:Cambridge University Press, 1992. xxxii + 695 pp. £55.00 Michael Dummett, The seas of language. Oxford:Clarendon Press, 1993. xvii + 482 pp. £40.00 Stephen Read,, Sophisms in medieval logic and grammar. Acts of the Ninth European Symposium for Medieval Logic and Semantics held at St Andrews, June 1990. Dordrecht, Boston, London:Kluwer Academic Publishers, 1993. xvii + 421pp. $157.50 James D. McCawley, Everything that linguists have always wanted to know about logic∗ ∗but were ashamed to ask. Second edition. Chicago and London:The University of Chicago Press, 1993. xxi + 633pp. £25.95/$37.50 ; £79.25/$113.75 Theodor Ebert, Dialektiker und frühe Stoiker bei Sextus Empiricus. Untersuchungen zur Entstehung der Aussagenlogik. Göttingen:Vandenhoeck & Ruprecht, 1991. 347 pp. DM 85.00 Entre la logique et la foi. Entretiens avec Joseph-M. Bochenski recueillis par Jan Parys. Translated from the Polish by Eric Morin-Aguilar. Montricher :Editions Noir-sur-Blanc, 1990. 353 pp. SFr 40.00 Noel Balzer, The human being as a logical thinker. Amsterdam and Atlanta:Rodopi 1993, 148 pp. No price stated R. I. G. Hughes, A philosophical companion to first-order logic. Indianapolis:Hackett, 1993, viii + 309 pp. No price stated Shahid Rahman, Über Dialoge, Protologische Kategorien und andere Seltenheiten, Frankfurt, Peter Lang Verlag, 1993. 318 pp. No price stated Claire Ortiz Hill, Word and object in Husserl, Frege, and Russell. The roots of twentieth century philosophy. Athens, Ohio:Ohio University Press, 1991. xiii + 215pp., $34.95