In this paper first order theories for nonmonotone inductive definitions are introduced, and a proof-theoretic analysis for such theories based on combined operator forms a la Richter with recursively inaccessible and Mahlo closure ordinals is given.

Philosophy of Science: A Unified Approach combines a general introduction to philosophy of science with an integrated survey of all its important subfields. As the book’s subtitle suggests, this excellent overview is guided methodologically by "a unified approach" to philosophy of science: behind the diversity of scientific fields one can recognize a methodological unity of the sciences. This unity is worked out in this book, revealing all the while important differences between subject areas. Structurally, this comprehensive book offers a two-part (...) approach, which makes it an excellent introduction for students new to the field and a useful resource for more advanced students. Each chapter is divided into two sections. The first section assumes no foreknowledge of the subject introduced, and the second section builds upon the first by bringing into the conversation more advanced, complementary topics. Definitions, key propositions, examples and figures overview all of the core material. At the end of every chapter there are selected readings and exercises . The book also includes a comprehensive bibliography and an index. (shrink)

The volume contains the written versions of all papers given at the workshop, divided into five chapters and followed by Alvin Goldman's replies in the sixth.

Together with its introduction, Language, Mind and Epistemology examines Davidson's unified stance towards philosophy by joining American and European authors ...

According to the paradigm of adaptive rationality, successful inference and prediction methods tend to be local and frugal. As a complement to work within this paradigm, we investigate the problem of selecting an optimal combination of prediction methods from a given toolbox of such local methods, in the context of changing environments. These selection methods are called meta-inductive strategies, if they are based on the success-records of the toolbox-methods. No absolutely optimal MI strategy exists—a fact that we call the “revenge (...) of ecological rationality”. Nevertheless one can show that a certain MI strategy exists, called “AW”, which is universally long-run optimal, with provably small short-run losses, in comparison to any set of prediction methods that it can use as input. We call this property universal access-optimality. Local and short-run improvements over AW are possible, but only at the cost of forfeiting universal access-optimality. The last part of the paper includes an empirical study of MI strategies in application to an 8-year-long data set from the Monash University Footy Tipping Competition. (shrink)

In this paper a new conception of foundation-oriented epistemology is developed. The major challenge for foundation-oriented justifications consists in the problem of stopping the justificational regress without taking recourse to dogmatic assumptions or circular reasoning. Two alternative accounts that attempt to circumvent this problem, coherentism and externalism, are critically discussed and rejected as unsatisfactory. It is argued that optimality arguments are a new type of foundation-oriented justification that can stop the justificational regress. This is demonstrated on the basis of a (...) novel result in the area of induction: the optimality of meta-induction. In the final section the method of optimality justification is generalized to deductive and abductive inferences. (shrink)

Jäger, G., Fixed points in Peano arithmetic with ordinals, Annals of Pure and Applied Logic 60 119-132. This paper deals with some proof-theoretic aspects of fixed point theories over Peano arithmetic with ordinals. It studies three such theories which differ in the principles which are available for induction on the natural numbers and ordinals. The main result states that there is a natural theory in this framework which is a conservative extension of Peano arithmeti.

In this paper I reconstruct and compare criteria of theoreticity that have been developed by Carnap, Sneed and proponents of the Munich school of structuralist philosophy of science. For this purpose I develop a unified framework in which one can transform model-theoretic theory representations into linguistic ones, and vice versa. This bridges the gap between statement and non-statement view and allows a precise comparison of linguistic and model-theoretic criteria of theoreticity. In the final part I suggest a system of improved (...) definitions of theoreticity and pre-theoreticity. (shrink)

The Diagnostic Understanding of Gestalt Theoretical Psychotherapy: In accordance with the basic thoughts of the Guideline, Gestalt Theoretical Psychotherapy acts on the conviction that diagnostic revelations and therapeutic change processes are inseparable. Even if each of them is related to different functions and thus to particular demands, an efficient patient support requires the professional and proper interplay of discovery and change processes throughout her therapy. Each new discovery is per se related to a change and may set off a series (...) of further changes, which may again trigger off new discoveries. As widely known, this may also happen when this whole process and this cause-and-effect-relation are neither intended, nor planned, nor insightfully administered or understood. The authors of the Guideline are, therefore, right to not only ascertain the fact that discovering and changing in psychotherapy are joint and intertwining processes, but also to postulate that the psychotherapist has to work on this intertwining process consciously and deliberately, guided by and in accordance with her particular scientific-methodological approach. Even in the diagnostic strand of psychotherapeutic work, Gestalt Theoretical psychotherapists let themselves be guided by the “characteristics of working at the living”, as they were elaborated by Wolfgang Metzger (1962) and transferred to psychotherapeutic applications by Hans-Jürgen P. Walter (1977) and his colleagues. Simultaneously, essential anthropological, epistemological and ethical home positions of Gestalt theory are concisely expressed therein. I am going to mention them briefly, reformulating them in reference to the diagnostic remit. By doing so, the accordance with the major viewpoints of the Guideline in the description of diagnostic processes in psychotherapy should become apparent. (shrink)

This paper deals with universes in explicit mathematics. After introducing some basic definitions, the limit axiom and possible ordering principles for universes are discussed. Later, we turn to least universes, strictness and name induction. Special emphasis is put on theories for explicit mathematics with universes which are proof-theoretically equivalent to Feferman's.

ArgumentAccording to Hermann von Helmholtz, free mobility of bodies seemed to be an essential condition of geometry. This free mobility can be interpreted either as matter of fact, as a convention, or as a precondition making measurements in geometry possible. Since Henri Poincaré defined conventions as principles guided by experience, the question arises in which sense experiential data can serve as the basis for the constitution of geometry. Helmholtz considered muscular activity to be the basis on which the form of (...) space could be construed. Yet, due to the problem of illusion inherent in the subject’s self-assessment of muscular activity, this solution yielded new difficulties, in that if the manifold is abstracted from rigid bodies which serve as empirical justification of the geometrical notion of space, then illusionary bodies will produce fictive manifolds. The present article is meant to disentangle these difficulties. (shrink)

In this paper we establish the proof-theoretic equivalence of (i) $\hbox {\sf ATR}$ and $\widehat{\hbox{\sf ID}}_{\omega}$ , (ii) $\hbox{\sf ATR}_0+ (\Sigma^1_1-\hbox{\sf DC})$ and $\widehat{\hbox {\sf ID}}_{<\omega^\omega} , and (iii) $\hbox {\sf ATR}+(\Sigma^1_1-\hbox{\sf DC})$ and $\widehat{\hbox {\sf ID}}_{<\varepsilon_0} $.

Proceedings of a symposium held Sept. 24-28, 1996 in Vienna, Austria.

The major components of a life in the academy - teaching, advising, publishing, research and service - are examined in this book. Practical, comprehensive, and engaging, the Handbook will appeal to a broad audience across all academic disciplines - from new professors to tenured faculty.