The "space" of Lascar strong types, on some sort and relative to a given complete theory T, is in general not a compact Hausdorff topological space. We have at least three aims in this paper. The first is to show that spaces of Lascar strong types, as well as other related spaces and objects such as the Lascar group Gal L of T, have well-defined Borel cardinalities. The second is to compute the Borel cardinalities of the known examples as well (...) as of some new examples that we give. The third is to explore notions of definable map, embedding, and isomorphism, between these and related quotient objects. We also make some conjectures, the main one being roughly "smooth if and only if trivial". The possibility of a descriptive set-theoretic account of the complexity of spaces of Lascar strong types was touched on in the paper [E. Casanovas, D. Lascar, A. Pillay and M. Ziegler, Galois groups of first order theories, J. Math. Logic1 305–319], where the first example of a "non-G-compact theory" was given. The motivation for writing this paper is partly the discovery of new examples via definable groups, in [A. Conversano and A. Pillay, Connected components of definable groups and o-minimality I, Adv. Math.231 605–623; Connected components of definable groups and o-minimality II, to appear in Ann. Pure Appl. Logic] and the generalizations in [J. Gismatullin and K. Krupiński, On model-theoretic connected components in some group extensions, preprint, arXiv:1201.5221v1]. (shrink)

0-categorical o-minimal structures were completely described by Pillay and Steinhorn 565–592), and are essentially built up from copies of the rationals as an ordered set by ‘cutting and copying’. Here we investigate the possible structures which an 0-categorical weakly o-minimal set may carry, and find that there are some rather more interesting examples. We show that even here the possibilities are limited. We subdivide our study into the following principal cases: the structure is 1-indiscernible, in which case all possibilities (...) are classified up to binary structure; the structure is 2-indiscernible, classified up to ternary structure; the structure is 3-indiscernible, in which case we show that it is k-indiscernible for every finite k. We also make some remarks about the possible structures of higher arities which an 0-categorical weakly o-minimal structure may carry. (shrink)

Il est une question fondamentale dont il semble pourtant qu’elle n’ait pas été posée: celle de savoir ce qui fait que le cogito soit effectivement un principe métaphysique, c’est-à-dire une vérité première. Il semble aussi que ce qui d’ordinaire tient lieu de réponse à cette question dans l’esprit des lecteurs de Descartes, c’est le sentiment vague qu’il s’agit là de la première vérité qui surgisse après la dévastation laissée par le doute universel de la Première Méditation, ou peut-être qui surgisse (...) au cœur de ce doute, puisque le doute ne s’autodétruit que pour faire place à ego sumOr s’en tenir à cela pour justifier le statut de principe métaphysique du cogito, c’est confondre priorité chronologique et primauté métaphysique ou épistémique: en effet, qu’y aurait-il dans le seul fait de se présenter ainsi qui assure que le cogito doive fonder d’autres connaissances, d’éventuelles sciences? Qu’est-ce qui empêcherait aussi qu’il ne soit lui-même assujetti à d’autres connaissances, plus fondamentales, et dont le méditant ne se serait peut-être pas encore aperçu? Il est vrai que cette confusion est compréhensible, puisque la primauté métaphysique du cogito coïncide effectivement avec sa priorité dans l’ordre des connaissancesMais dans le doute ambiant, celle-ci n’est en réalité qu’un effet de celle-là, et le simple fait de constater l’une ne revient pas à être assuré de l’autre. Il ne peut s’agir donc que d’une coïncidence, et la question se pose dès lors de savoir comment se traduit sa primauté, c’est-à-dire comment doivent se concevoir ses rapports avec le reste de nos éventuelles connaissances. (shrink)

We consider the potential impact of Computer Supported Cooperative Work, with special reference to large technically advanced projects involving several organizations. It is vital that such projects are managed efficiently, without delays, since a product that reaches the market a few months earlier than its competitors enjoys a great advantage. Traditional methods of coordinating large projects, based on hierarchical communication, tend to produce delays, since technicians at remote sites are obliged to solve coordination problems by passing them up the hierachy. (...) It would be better if such problems were solved by improvising conferences among the technicians; Computer Supported Cooperative Work will provide the technical means of implementing this heterarchical style of management without losing control of the project. The use of computers as a social medium raises methodological and ethical issues which are discussed in the final section. (shrink)

Contrairement à ce que peut suggérer l ’ expression de lumière naturelle lorsqu ’ il en est question, le cogito n ’ est pas une vérité de la raison. La raison est révoquée en doute au moment où il survient et ne saurait donc en assurer la vérité. Ce rôle est dévolu à la réflexivité de l ’ acte par lequel la pensée se constitue son propre objet lorsqu ’ elle affirme Je suis : immédiatement accessible à elle-même, c ’ (...) est une chose dans le monde, et par conséquent un existant, qu ’ elle saisit ainsi, non pas une représentation. Le cogito est ainsi inextricablement impliqué dans un acte certes, mais cet acte n ’ est pas le performatif qu ’ a voulu en faire Hintikka. La proposition qui l ’ exprime s ’ apparente en fait à une contingente : selon l ’ analyse ici proposée, il lui est en effet possible d ’ être fausse. (shrink)

Berkeley is commonly regarded as an idealist whose system is saved from subjectivism only by the advent of a God more violently ex machina than the God of any other philosopher. I hope to show that this accusation rests on a misunderstanding of his central theory, a misunderstanding which gives God a place both inconsistent with his main premisses and useless in his system. I hope also to display by quotation the real Berkeley, whose theory of God's place and nature (...) is directly supported by argument and consistent with his premisses, and makes a system which, if it is less than a completely coherent philosophy, is more than an episcopal assumption. (shrink)

This chapter introduces the three central features of the epistemological framework that guides the prescriptions of Ameliorative Psychology. It is argued that this framework offers a new way to think about applied epistemology. In particular, it suggests that there are four and only four ways for people to improve their reasoning.

This chapter begins by giving two reasons as to why epistemology is important: epistemology guides reasoning, and people don't fully appreciate the risks and dangers of poor reasoning the importance of epistemology. It then introduces the basic motives and methods of the epistemology developed in the book. Topics covered include the standard analytic approach to epistemology, the philosophy of science approach to epistemology, the theories generated by the two approaches, and whether scientific investigation into normative epistemology possible.

This chapter uses Strategic Reliabilism to resolve two debates about whether certain experimental findings demonstrate deep and systematic failures of human reasoning. It illustrates one of the main benefits of the current approach to epistemology: it can be used to adjudicate disputes that arise in psychology that are, at bottom, normative epistemological disputes about the nature of good reasoning.

This chapter discusses Statistical Prediction Rules and provides an explanation for their success. SPRs are simple, formal rules that have been shown to be typically more reliable, than the predictions of human experts on a wide variety of problems. Based on testable results, psychology can make normative recommendations about how we ought to reason. The branches of psychology that provide normative recommendations are dubbed as ‘Ameliorative Psychology’. Two central lessons of Ameliorative Psychology are that when it comes to social judgment, (...) proper unit weight models outperform humans in terms of reliability and improper unit weight models often perform nearly as well as proper models and therefore better than humans. It is argued that the reason people resist this ‘practical conclusion’ is partly because the SPR results are noxious to our conception of ourselves as good reasoners. Further, they undermine our hope — so evident in the a priorism of so much contemporary epistemology — that we can be experts at recognizing good reasoning without massive empirical aid. (shrink)

Everyman’s Library commemorates its fiftieth anniversary very aptly with this issue as its thousandth volume of a classic text of some 2,300 years of age, which through varying fortunes has been a major influence in European culture. As a transcendental science Metaphysics makes no concession to the semi-curious; Aristotle’s inaugurating textbook is understandably concentrated and obscure. A literal version of this formidable text would have no appeal to the general reader, innocent largely of the Greek idiom and of philosophical jargon, (...) while a personal paraphrase could not carry the authentic voice of a past master. Mr. Warrington simply takes the existing Oxford version, retranslating it into easier, more fluent English and rearranging its fourteen books into a free, logical order. In this he is guided by their matter and by the critico-historical views of Jaeger and Ross, outlined in a short Introduction by Sir David himself. He has added chapter titles, numbered sections, prefixing their main groups with a short summary of contents and has courageously kept clear the main line of Aristotle’s argument by relegating all parentheses to footnotes, to which he adds his own identification of historical references. Radical re-arrangement justifies itself by success—here a forbidding classic is presented with the immediate, systematic clarity of a modern text. (shrink)

This competent work in a growing, scholarly series is regrettably the last publication of the zealously expert Father Philotheus Boehner, who died in May, 1955, before the first fruit appeared of his projected critical edition of the philosophical and theological works of his misunderstood fourteenth century confrère. This is an apt introduction for the research student to a set of Ockham’s representative philosophical texts, printed in Latin and English on opposite pages. Ockham’s concisely technical style is notoriously difficult for the (...) tyro—demanding to be ‘ruminated’, in the editor’s transferred phrase—and Fr. Boehner has been careful to render it in expansive and easy-going English. In addition to a select bibliography of Ockham’s writings and of commentaries upon them, Fr. Boehner concisely expounds his life and the main principles of his philosophy according to the order of the following illustrative texts. (shrink)

We show that the structure (C,+,·) has no proper non locally modular reducts which contain +. In other words, if $X \subset \mathbf{C}^n$ is constructible and not definable in the module structure (C,+,λ a ) a ∈ C (where λ a denotes multiplication by a) then multiplication is definable in (C,+,X).