Eric Martin and Daniel N. Osherson present a theory of inductive logic built on model theory. Their aim is to extend the mathematics of Formal Learning Theory to a more general setting and to provide a more accurate image of empirical inquiry. The formal results of their study illuminate aspects of scientific inquiry that are not covered by the commonly applied Bayesian approach.

In seiner letzten Schrift unternimmt Husserl den Versuch, auf dem Wege einer teleologisch-historischen Besinnung auf die Ursprünge unserer kritischen wissenschaftlichen und philosophischen Situation die Notwendigkeit einer transzendentalphänomenologischen Umwendung der Philosophie zu begründen. Er geht von seinem Begriff der "Lebenswelt" aus und entwickelt eine auf diesen Zentralbegriff seiner Spätphilosophie gegründete eigenständige Einleitung in die transzendentale Phänomenologie.

Mit den "Ideen zu einer reinen Phänomenologie und phänomenologischen Philosophie" von 1913, von ihm selbst nur als eine "Allgemeine Einführung in die reine Phänomenologie" angezeigt, zog Edmund Husserl die Konsequenz aus seinen Logischen Untersuchungen (PhB 601), die ihn 1900/01 berühmt gemacht hatten: Ausgehend von der dort entwickelten Phänomenologie der intentionalen Erlebnisse sieht er jetzt in der Aufdeckung der Leistungen des "reinen Bewußtseins", dem die uns bekannte natürliche Welt nur als "Bewußtseinskorrelat" gegeben ist, den eigentlichen Gegenstand philosophischer Erkenntnis und in den (...) von ihm eingeführten methodologischen Begriffen der "Reduk tion" und der "Epoché" den Weg, sich über die Beschaffenheit dieses "reinen Bewußtseins", aus dem alle Erkenntnis entspringt, Klarheit zu verschaffen. Die Ausgabe bietet Husserls Schrift text- und seitengleich nach Band III/1 der Husserliana, herausgegeben von Karl Schuhmann; beigegeben sind Husserls Nachwort zu den Ideen von 1930 aus Band V der Husserliana, herausgegeben von Marly Biemel, sowie ein umfangreiches Namen- und Sachregister von Elisabeth Ströker. (shrink)

Several of these essays have been printed whole in journals; others are in varying degrees new. Two main themes run through them. One is the problem of meaning, particularly as involved in the notion of an analytic statement. The other is the notion of ontological, commitment, particularly as involved in the problem of universals.

The twentieth century has witnessed an unprecedented 'crisis in the foundations of mathematics', featuring a world-famous paradox (Russell's Paradox), a challenge to 'classical' mathematics from a world-famous mathematician (the 'mathematical intuitionism' of Brouwer), a new foundational school (Hilbert's Formalism), and the profound incompleteness results of Kurt Gödel. In the same period, the cross-fertilization of mathematics and philosophy resulted in a new sort of 'mathematical philosophy', associated most notably (but in different ways) with Bertrand Russell, W. V. Quine, and Gödel himself, (...) and which remains at the focus of Anglo-Saxon philosophical discussion. The present collection brings together in a convenient form the seminal articles in the philosophy of mathematics by these and other major thinkers. It is a substantially revised version of the edition first published in 1964 and includes a revised bibliography. The volume will be welcomed as a major work of reference at this level in the field. (shrink)

We prove the following Main Theorem: $ZF + AD + V = L(R) \Rightarrow DC$ . As a corollary we have that $\operatorname{Con}(ZF + AD) \Rightarrow \operatorname{Con}(ZF + AD + DC)$ . Combined with the result of Woodin that $\operatorname{Con}(ZF + AD) \Rightarrow \operatorname{Con}(ZF + AD + \neg AC^\omega)$ it follows that DC (as well as AC ω ) is independent relative to ZF + AD. It is finally shown (jointly with H. Woodin) that ZF + AD + ¬ DC (...) R , where DC R is DC restricted to reals, implies the consistency of ZF + AD + DC, in fact implies R # (i.e. the sharp of L(R)) exists. (shrink)

In this paper, we sketch the development of two important themes of modern set theory, both of which can be regarded as growing out of work of Kurt Gödel. We begin with a review of some basic concepts and conventions of set theory.§0. The ordinal numbers were Georg Cantor's deepest contribution to mathematics. After the natural numbers 0, 1, …, n, … comes the first infinite ordinal number ω, followed by ω + 1, ω + 2, …, ω + ω, (...) … and so forth. ω is the first limit ordinal as it is neither 0 nor a successor ordinal. We follow the von Neumann convention, according to which each ordinal number α is identified with the set {ν ∣ ν α} of its predecessors. The ∈ relation on ordinals thus coincides with <. We have 0 = ∅ and α + 1 = α ∪ {α}. According to the usual set-theoretic conventions, ω is identified with the first infinite cardinal ℵ0, similarly for the first uncountable ordinal number ω1 and the first uncountable cardinal number ℵ1, etc. We thus arrive at the following picture:The von Neumann hierarchy divides the class V of all sets into a hierarchy of sets Vα indexed by the ordinal numbers. The recursive definition reads: ;Vλ = ∪v<λVv for limit ordinals λ. We can represent this hierarchy by the following picture. (shrink)

§1. Introduction. Among the most remarkable discoveries in set theory in the last quarter century is the rich structure of the arithmetic of singular cardinals, and its deep relationship to large cardinals. The problem of finding a complete set of rules describing the behavior of the continuum function 2ℵα for singular ℵα's, known as the Singular Cardinals Problem, has been attacked by many different techniques, involving forcing, large cardinals, inner models, and various combinatorial methods. The work on the singular cardinals (...) problem has led to many often surprising results, culminating in a beautiful theory of Saharon Shelah called the pcf theory. The most striking result to date states that if 2ℵn < ℵω for every n = 0, 1, 2, …, then 2ℵω < ℵω4.In this paper we present a brief history of the singular cardinals problem, the present knowledge, and an introduction into Shelah's pcf theory. In Sections 2, 3 and 4 we introduce the reader to cardinal arithmetic and to the singular cardinals problems. Sections 5, 6, 7 and 8 describe the main results and methods of the last 25 years and explain the role of large cardinals in the singular cardinals problem. In Section 9 we present an outline of the pcf theory.§2. The arithmetic of cardinal numbers. Cardinal numbers were introduced by Cantor in the late 19th century and problems arising from investigations of rules of arithmetic of cardinal numbers led to the birth of set theory. The operations of addition, multiplication and exponentiation of infinite cardinal numbers are a natural generalization of such operations on integers. Addition and multiplication of infinite cardinals turns out to be simple: when at least one of the numbers κ, λ is infinite then both κ + λ and κ·λ are equal to max {κ, λ}. In contrast with + and ·, exponentiation presents fundamental problems. In the simplest nontrivial case, 2κ represents the cardinal number of the power set P, the set of all subsets of κ. (Here we adopt the usual convention of set theory that the number κ is identified with a set of cardinality κ, namely the set of all ordinal numbers smaller than κ. (shrink)

I examine various claims to the effect that Cantor's Continuum Hypothesis and other problems of higher set theory are ill-posed questions. The analysis takes into account the viability of the underlying philosophical views and recent mathematical developments.

The old evidence problem affects any probabilistic confirmation measure based on comparing pr(H/E) and pr(H). The article argues for the following points: (1) measures based on likelihood ratios also suffer old evidence difficulties; (2) the less-discussed synchronic old evidence problem is, in an important sense, the most acute; (3) prominent attempts to solve or dissolve the synchronic problem fail; (4) a little-discussed variant of the standard measure avoids the problem, in an appealing way; and (5) this measure nevertheless reveals a (...) different problem for probabilistic confirmation measures, a problem that is unlikely to lend itself to formal solution. (shrink)

Is the continuum hypothesis still open? If we interpret it as finding the laws of cardinal arithmetic, it was thought to be essentially solved by the independence results of Godel and Cohen with some isolated positive results. It was expected that only more independence results remained to be proved. The author has come to change his view. This enables us to get new results for the conventional cardinal arithmetic, thus supporting the interest in our view. We also find other applications, (...) extend older methods of using normal fiters and prove the existence of Jonsson algebra. (shrink)

Dieser Band enthält Husserls letzte grosse Arbeit, an der er von 1934 bis 1937 arbeitete. Husserl weist darin die Probleme auf, die seiner Ansicht nach zu der Krise geführt haben, in der die Menschheit der Gegenwart sich befindet. Er verfolgt den Ursprung dieser Krise zurück bis zur Entstehung der neuzeitlichen mathematischen Naturwissenschaften bei Galilei, um aufzuweisen, wie es zu der verhängnisvollen Spaltung des physikalistischen Objektivismus und des transzendentalen Subjektivismus gekommen ist. Die Geschichte der neuzeitlichen Philosophie wird von Descartes über Locke (...) - Berkeley - Hume bis zu Kant verfolgt. Husserl stellt dar, wie es das eigentliche Anliegen der Phänomenologie ist den verhängnisvollen Riss zu überwinden, indem sie den Rückgang zu dem Sinnesfundament vollzieht, das in den Wissenschaften selbst und für diese verborgen bleibt. In diesem Zusammenhang kommt gerade der Wissenschaft vom Menschen, der Psychologie, eine fundamentale Bedeutung zu, allerdings einer Psychologie, die auf der Phänomenologie gründet und von ihren Erkenntnissen ausgeht. Ausser dem erhaltenen Haupttext befinden sich im Husserl-Archiv noch zahlreiche "Forschungsmanuskripte", die im Zusammenhang mit der Krisis-Problematik entstanden sind. Um auch in sie Einblick zu geben wurde eine umfassende Auswahl in Form von Beilagen veröffentlicht, sowie noch einige selbständige Abhandlungen die die Entstehungsgeschichte des Werkes erhellen. (shrink)

Does V = L? Is the Axiom of Constructibility true? Most people with an opinion would answer no. But on what grounds? Despite the near unanimity with which V = L is declared false, the literature reveals no clear consensus on what counts as evidence against the hypothesis and no detailed analysis of why the facts of the sort cited constitute evidence one way or another. Unable to produce a well-developed argument one way or the other, some observers despair, retreating (...) to unattractive fall-back positions, e.g., that the decision on whether or not V = L is a matter of personal aesthetics. I would prefer to avoid such conclusions, if possible. If we are to believe that L is not V, as so many would urge, then there ought to be good reasons for this belief, reasons that can be stated clearly and subjected to rational evaluation. Though no complete argument has been presented, the literature does contain a number of varied argument fragments, and it is worth asking whether some of these might be developed into a persuasive case.One particularly simple approach would be to note that the existence of a measurable cardinal implies that V ≠ L,1and to argue that there is a measurable cardinal. The drawback to this approach is that its implying V ≠ L cannot then be counted as evidence in favor of MC, as it often is. Indeed, there seems to have been considerable sentiment against V = L even before the proof of its negation from MC,2and this sentiment must either be accounted for as reasonable or explained away as an aberration of some kind. (shrink)

Part of the ambiguity lies in the various points of view from which this question might be considered. The crudest di erence lies between the point of view of the working mathematician and that of the logician concerned with the foundations of mathematics. Now some of my fellow mathematical logicians might protest this distinction, since they consider themselves to be just more of those \working mathematicians". Certainly, modern logic has established itself as a very respectable branch of mathematics, and there (...) are quite a few highly technical journals in logic, such as The Journal of Sym-. (shrink)