Bryson Brown

In this paper we introduce a paraconsistent reasoning strategy, Chunk and Permeate. In this, information is broken up into chunks, and a limited amount of information is allowed to flow between chunks. We start by giving an abstract characterisation of the strategy. It is then applied to model the reasoning employed in the original infinitesimal calculus. The paper next establishes some results concerning the legitimacy of reasoning of this kind - specifically concerning the preservation of the consistency of each chunk and concludes with some other possible applications and technical questions

Empirical adequacy is a central notion in van Fraassen's empiricist view of science. I argue that van Fraassen's account of empirical adequacy in terms of a partial isomorphism between certain structures in some model(s) of the theory and certain actual structures (the observables) in the world, is untenable. The empirical adequacy of a theory can only be tested in the context of an accepted practice of observation. But because the theory itself does not determine the correct practice of observation, its failure to pass the test does not show the failure of an isomorphism between the empirical substructure of some model(s) of the theory and observable structures in nature. Further, because the choice of a practice of observation is a pragmatic one grounded in epistemic goals we seek in observation, van Fraassen's anthropocentric view of observability is epistemically unmotivated.

B. H. Slater has argued that there cannot be any truly paraconsistent logics, because it's always more plausible to suppose whatever "negation" symbol is used in the language is not a real negation, than to accept the paraconsistent reading. In this paper I neither endorse nor dispute Slater's argument concerning negation; instead, my aim is to show that as an argument against paraconsistency, it misses (some of) the target. A important class of paraconsistent logics - the preservationist logics - are not subject to this objection. In addition I show that if we identify logics by means of consequence relations, at least one dialetheic logic can be reinterpreted in preservationist (non-dialetheic) terms. Thus the interest of paraconsistent consequence relations - even those that emerge from dialetheic approaches - does not depend on the tenability of dialetheism. Of course, if dialetheism is defensible, then paraconsistent logic will be required to cope with it. But the existence (and interest) of paraconsistent logics does not depend on a defense of dialetheism

An argument for skepticism about the past exploits a circularity in the arguments connecting present observations to claims about past events. Arguments supporting claims about the past depend on current observations together with processes linking current observations to those claims. But knowledge of processes requires knowledge of the past: Knowledge of the present alone cannot provide evidence for claims about the past. A practical, coherentist response to this challenge rejects the assumption that we come to the problem with no information about the past. Beginning with partial and imperfect information about the past, a coherentist tests ideas about processes against the particular evidence of traces left by past processes, and particular claims about the past against ideas about the processes linking those events to present traces. However, this common-sense response is inadequate when faced with a radical skeptic prepared to insist on the problem of the criterion. An answer to this radicalskeptic can be drawn from Wilfrid Sellars ‘bootstrap’ argument in “Empiricism and the Philosophy of Mind.” The result is a better response to the problem of the criterion than Chisholm’s ‘particularism’.

In A Treatise of Human Nature Hume wrote a long section titled “Of skepticism with regard to the senses.” The discussion examines two key features of our beliefs about the objects making up the external world: 1. They continue to exist, even when unperceived. 2. They are distinct from the mind and its perceptions. The upshot of the discussion is a graceful sort of intellectual despair:I cannot conceive how such trivial qualities of the fancy, conducted by such false suppositions, can ever lead to any solid and rational system... ’Tis a gross illusion to suppose, that our resembling perceptions are numerically the same; and ’tis this illusion, which leads us into the opinion, that these perceptions are uninterrupted, and are still existent, even when they are not present to the senses. This is the case with our popular system. And as to our philosophical one, ’tis liable to the same difficulties; and is over-and-above loaded with this absurdity, that it at once denies and establishes the vulgar supposition. (Treatise, 217-8)These notes examine the argument of this section of the Treatise in detail. The upshot is that Hume’s despair is founded on an error. The notes finish by drawing some lessons about the epistemology of our common-sense world view.

Nicholas Rescher has argued we must tolerate inconsistency because of our cognitive limitations. He has also produced, together with R. Brandom, a serious attempt at exploring the logic of inconsistency. Inconsistency tolerance calls for a systematic rewriting of our logical doctrines: it requires a paraconsistent logic. However, having given up all aggregation of premises, Rescher's proposal for a paraconsistenl logic fails to account for the reductive reasoning Rescher appeals to in his account of inconsistency tolerance. A non-adjunctive logic developed by P.K. Schotch and RE. Jennings provides just what Rescher's logic is lacking: It allows a tolerant attitude toward inconsistency while giving an account of reductive reasoning

Whether we’re reading H.G. Wells, Robert Heinlein, Ray Bradbury, or Kurt Vonnegut, time travel is a wonderful narrative trick, freeing a story from the normal ‘one damn thing after another’ progression of time. But many philosophers claim it can never be more than that because backwards causation in general, and time travel in particular, are logically impossible.In this paper I examine one type of argument commonly given for this disappointing conclusion: the time travel paradoxes. Happily for science fiction fans, these arguments fall far short of showing what they are intended to show. Why they fail can be better understood in the light of an analogy between these arguments and some arguments libertarians offer against determinism.

Paraconsistent logic is an area of philosophical logic that has yet to find acceptance from a wider audience. The area remains, in a word, disreputable. In this essay, we try to reassure potential consumers that it is not necessary to become a radical in order to use paraconsistent logic. According to the radicals, the problem is the absurd classical account of contradiction: Classically inconsistent sets explode only because bourgeois classical semantics holds, in the face of overwhelming evidence to the contrary, that both A and ∼ A cannot simultaneously be true! We suggest (more modestly) that there is, at least sometimes, something else worth preserving, even in an inconsistent, unsatisfiable premise set. In this paper we present, in a new guise, a very general version of this “preservationist” approach to paraconsistency.

Darwinian natural selection draws on Malthus’ harsh vision of human society to explain how organisms come to be adapted to their environments. Natural selection produces the appearance of teleology, but requires only efficient causal processes: undirected, heritable variation combined with effects of the variations on survival and reproduction. This paper draws a sharp distinction between the resulting form of backwards-directed teleology and the future-directed teleology we ascribe to intentional human activity. Rather than dismiss teleology as mere illusion, the paper concludes with an account of how future-directed teleology came to be a justifiable part of how we understand ourselves

The most pressing problems facing humanity today - over-population, energy shortages, climate change, soil erosion, species extinctions, the risk of epidemic disease, the threat of warfare that could destroy all the hard-won gains of civilization, and even the recent fibrillations of the stock market - are all ecological or have a large ecological component. in this volume philosophers turn their attention to understanding the science of ecology and its huge implications for the human project. To get the application of ecology to policy or other practical concerns right, humanity needs a clear and disinterested philosophical understanding of ecology which can help identify the practical lessons of science. Conversely, the urgent practical demands humanity faces today cannot help but direct scientific and philosophical investigation toward the basis of those ecological challenges that threaten human survival. This book will help to fuel the timely renaissance of interest in philosophy of ecology that is now occurring in the philosophical profession. Provides a bridge between philosophy and current scientific findings Covers theory and applications Encourages multi-disciplinary dialogue

Just what forms do (or should) our cognitive attitudes towards scientific theories take? The nature of cognitive commitment becomes particularly puzzling when scientists' commitments are) inconsistent. And inconsistencies have often infected our best efforts in science and mathematics. Since there are no models of inconsistent sets of sentences, straightforward semantic accounts fail. And syntactic accounts based on classical logic also collapse, since the closure of any inconsistent set under classical logic includes every sentence. In this essay I present some evidence that there really was a substantial cognitive commitment to OQT, and that some of its characteristics have a simple and straightforward explanation in terms of a model based on a form of paraconsistent logic.

Scientific inquiry is typically focused on particular questions about particular objects and properties. This leads to a multiplicity of models which, even when they draw on a single, consistent body of concepts and principles, often employ different methods and assumptions to model different systems. Pluralists have remarked on how scientists draw on different assumptions to model different systems, different aspects of systems and systems under different conditions and defended the value of distinct, incompatible models within science at any given time. Paraconsistentists have proposed logical strategies to avoid trivialization when inconsistencies arise by a variety of means. Here we examine how chunk and permeate, a simple approach to paraconsistent reasoning which avoids heterodox logic by confining commitments to separate contexts in which reasoning with them is taken to be reliable while allowing ‘permeation’ of some conclusions into other contexts, can help to systematize pluralistic reasoning across the boundaries of plural contexts, using regional climate models as an example. The result is a kind of unity for science—but a unity achieved by the constrained exchange of specified information between different contexts, rather than the closure of all commitments under some paraconsistent consequence relation.

Two aims are at work in James Brown's Smoke and Mirrors: to defend realism against some of its recent detractors, and to expound his own programmatic commitment to a Platonic form of realism. I am sympathetic to his first goal, and dubious about the second, so, as Brown himself predicts, I am enthusiastic about the critical part of the book but critical of his Platonic project. But I will begin this review with a hearty recommendation. Smoke and Mirrors is clear, articulate, perceptive, occasionally provocative, and a healthy antidote to the sceptical pessimism about science that one encounters so often today.

David Sanford's If P, Then Q is an ambitious book, aimed at two difficult tasks and addressed to two audiences. It combines a survey of historical and contemporary work on-conditionals with a presentation-of, Sanford's personal views. And it is addressed to both undergraduate students, without, logical training, and professionals seriously interested in conditionals. It is marred by the impossibility of achieving both aims in a book this size, and by the strains of simultaneously addressing audiences with such different needs and interests.

Two aims are at work in James Brown'sSmoke and Mirrors:to defend realism against some of its recent detractors, and to expound his own programmatic commitment to a Platonic form of realism. I am sympathetic to his first goal, and dubious about the second, so, as Brown himself predicts, I am enthusiastic about the critical part of the book but critical of his Platonic project. But I will begin this review with a hearty recommendation.Smoke and Mirrorsis clear, articulate, perceptive, occasionally provocative, and a healthy antidote to the sceptical pessimism about science that one encounters so often today.