The eminent philosopher of science Carl G. Hempel, Stuart Professor of Philosophy at Princeton University and a Past President of the American Philosophical Association, has had a long and distinguished academic career in the course of which he has been professorial mentor to some of America's most distinguished philosophers. This volume gathers together twelve original papers by Hempel's students and associates into a volume intended to do homage to Hempel on the occasion of his 65th year in 1970. The papers are grouped around the unifying topic of Hempel's own interests in logic and philosophy of science, the great majority dealing with issues on inductive logic and the theory of scientific explanatio- problems to which Hempel has devoted the bulk of his outstandingly fruitful efforts. With the approach of 'Peter' Hempel's 65th birthday, an editorial committee sprang into being by an uncannily spontaneous process to prepare to commemorate this event with an appropriate Festschrift. The editors were pleased to receive unfailingly prompt and efficient coopera tion on the part of all contributors. The responsibility of seeing the work through the press was assumed by Nicholas Rescher. The editors are grateful to all concerned for their collaboration. ALAN ROSS ANDERSON PAUL BENACERRAF ADOLF GRUNBAUM GERALD J. MASSEY NICHOLAS RESCHER RICHARD S. RUDNER TABLE OF CONTENTS PREFACE V PAUL OPPENHEIM: Reminiscences of Peter 1 w. v. QUINE: Natural Kinds 5 JAAKKO HINTIKKA: Inductive Independence and the Paradoxes of Confirmation 24 WESLEY c."

The aim of the book is to introduce the reader to some new areas oflogic which have yet to find their way into the bulk of modern logic books written from the more orthodox direction of the mainstream of develop ments. Such a work seems to me much needed, both because of the in trinsic value and increasing prominence of the nonstandard sector of logic, and because this particular sector is of the greatest interest from the standpoint of philosophical implications and applications. This book unites a series of studies in philosophical logic, drawing for the most part on material which I have contributed to the journal liter ature of the subject over the past ten years. Despite the fact that some of these essays have been published in various journals at different times, they possess a high degree of thematic and methodological unity. All of these studies deal with material of substantial current interest in philo sophical logic and embody a fusion of the modern techniques of logical and linguistic-philosophical analysis for the exploration of areas of logic that are of substantial philosophical relevance."

The present publication forms part of a projected book that F. P. Ramsey drafted but never completed. It survived among his papers and ultimately came into the possession of the University of Pittsburgh in the circumstances detailed in the Editor's Introduction. Our hope in issuing this work at this stage - some sixty years after Ramsey's premature death at the age of 26 - is both to provide yet another token of his amazing philosophical creativity, and also to make available an important datum for the still to be written history of the development of philosophical analysis. This is a book whose appearance will, we hope and expect, be appreciated both by those interested in linguistic philosophy itself and by those concerned for its historical development in the present century. EDITORS'INTRODUCTION 1. THE RAMSEY COLLECTION Frank Plump ton Ramsey (22 February 1903 -19 January 1930) was an extra ordinary scholarly phenomenon. Son of a distinguished mathematician and President of Magdalene College, Cambridge and brother of Arthur Michael, eventual Archbishop of Canterbury, Ramsey was closely connected with Cambridge throughout his life, ultimately becoming lecturer in Mathematics in the University. Notwithstanding his great mathematical talent, it was primarily logic and philosophy that engaged his interests, and he wrote original and important contributions to logic, semantics, epistomology, probability theory, philosophy of science, and economics, in addition to seminal work in the foundations of mathematics."

The aim of this monograph is to expound the conceptions of temporalized modality at issue in various Arabic logical texts. I claim to have been able to make good logical sense of doctrines of which even the later Arab logicians themselves came to despair. In the process, a substantially new area of the history of logic has come into a clear view. I am indebted to Anne Cross (Mrs. Michael) Pelon and especially Mr. Bas van Fraassen for assistance in the research. Miss Dorothy Henle merits my thanks for preparing the difficult typescript for the printer and helping to see the book through the press. Also, I am grateful to the Editors of Foun dations of Language for inviting inclusion of the monograph in the Supple mentary Series of the journal. The present work is part of a series of studies of Arabic contributions to logic supported by research grants from the National Science Foundation. It affords me much pleasure to record my sincere thanks for this assistance."

Leibniz said with a mixture of admiration and inspiration that the Duchess Sophie of Hannover always wanted to know the reason why behind the reason why. And that is just how rationality works: it wants to leave no loose ends to understanding, seeking to enable us to understand things through to the bitter end. In the twelve chapters that make up Satisfying Reason, Rescher develops and defends the following perspective: That rationality is a cardinal virtue in cognitive matters. That this is not something simple and cut-and-dried: in the pursuit of truth through the development of knowledge we face obstacles -- sometimes even insuperable ones. All that we can do is the best we can, realizing that even our very best may still be imperfect. Nevertheless, the venture is far from hopeless. While absolutes are unattainable in the cognitive venture, some solutions are situationally optimal, being comparatively the best that can be managed under the circumstances. That reason itself enables us to come to terms with this state of affairs, urging us to accept the best we can do as good enough. Satisfying Reason is an explanation of the presuppositions and methods of rational enquiry, an original exercise in metaknowledge, developing a systematic body of knowledge about the scope and limits of knowledge itself.

The essays included in this volume are a mixture of old and new. Three of them make their first appearance in print on this occa sion (Nos III, IV, and V). The remaining four are based upon materials previously published in learned journals or anthologies. (However, these previously published papers have been revised and, generally, expanded for inclusion here.) Detailed acknowl edgement of prior publications is made in the notes to the relevant articles. I am grateful to the editors of these several publications for their kind permission to use this material. I am grateful to an anonymous reader for the Western Ontario Series for some useful corrigenda. And I should like to thank John Horty and Lily Knezevich for their help in seeing this material through the press. NICHOLAS RESCHER Pittsburgh, Pennsylvania May, 1980 xi INTRODUCTION The unifying theme of these essays is their concern with Leibniz's metaphysics of nature. In particular, they revolve about his cos mology of creation and his conception of the real world as one among infinitely many equipossible alternatives."

This volume collects together eleven essays in epistemology, written during the past three years. They are mostly unpublished, just four of them having appeared previously (numbers two, three, four and eleven). Detailed acknowledgement of prior publication is made in the notes to the relevant chapters. I am indebted to the editors of the several publications involved for their kind permission to use this material. And I am particularly grateful to my friend, Professor Mario Bunge, for his interest in my work and for his willingness to include this sample of it in his 'Episteme' series. NICHOLAS RESCHER Pittsburgh, PA December, 1986 xi INTRODUCTION The philosophy of knowledge covers a vast and enormously diversified terrain. Within this broad area, the essays that comprise the present book deal specifically with the following issues: 1. The moral dimension of inquiry - in particular, scientific inquiry into the ways of the world (Chapter 1) 2. The epistemic status of such cognitive 'values' of inquiry as - coherence (Chapter 2) - consistency (Chapter 3) - completeness (Chapter 4) 3. The cognitive bearing of probabilistic considerations (Chapters 5 and 6) 4. The epistemic status of certain ideal desiderata of cognition, such as - totality (Chapter 7) - precision (Chapter 8) - exactness (Chapter 9) 5.

The present publication forms part of a projected book that F. P. Ramsey drafted but never completed. It survived among his papers and ultimately came into the possession of the University of Pittsburgh in the circumstances detailed in the Editor's Introduction. Our hope in issuing this work at this stage - some sixty years after Ramsey's premature death at the age of 26 - is both to provide yet another token of his amazing philosophical creativity, and also to make available an important datum for the still to be written history of the development of philosophical analysis. This is a book whose appearance will, we hope and expect, be appreciated both by those interested in linguistic philosophy itself and by those concerned for its historical development in the present century. EDITORS'INTRODUCTION 1. THE RAMSEY COLLECTION Frank Plump ton Ramsey (22 February 1903 -19 January 1930) was an extra ordinary scholarly phenomenon. Son of a distinguished mathematician and President of Magdalene College, Cambridge and brother of Arthur Michael, eventual Archbishop of Canterbury, Ramsey was closely connected with Cambridge throughout his life, ultimately becoming lecturer in Mathematics in the University. Notwithstanding his great mathematical talent, it was primarily logic and philosophy that engaged his interests, and he wrote original and important contributions to logic, semantics, epistomology, probability theory, philosophy of science, and economics, in addition to seminal work in the foundations of mathematics."

Leibniz said with a mixture of admiration and inspiration that the Duchess Sophie of Hannover always wanted to know the reason why behind the reason why. And that is just how rationality works: it wants to leave no loose ends to understanding, seeking to enable us to understand things through to the bitter end. In the twelve chapters that make up Satisfying Reason, Rescher develops and defends the following perspective: That rationality is a cardinal virtue in cognitive matters. That this is not something simple and cut-and-dried: in the pursuit of truth through the development of knowledge we face obstacles -- sometimes even insuperable ones. All that we can do is the best we can, realizing that even our very best may still be imperfect. Nevertheless, the venture is far from hopeless. While absolutes are unattainable in the cognitive venture, some solutions are situationally optimal, being comparatively the best that can be managed under the circumstances. That reason itself enables us to come to terms with this state of affairs, urging us to accept the best we can do as good enough. Satisfying Reason is an explanation of the presuppositions and methods of rational enquiry, an original exercise in metaknowledge, developing a systematic body of knowledge about the scope and limits of knowledge itself.

This volume collects together eleven essays in epistemology, written during the past three years. They are mostly unpublished, just four of them having appeared previously (numbers two, three, four and eleven). Detailed acknowledgement of prior publication is made in the notes to the relevant chapters. I am indebted to the editors of the several publications involved for their kind permission to use this material. And I am particularly grateful to my friend, Professor Mario Bunge, for his interest in my work and for his willingness to include this sample of it in his 'Episteme' series. NICHOLAS RESCHER Pittsburgh, PA December, 1986 xi INTRODUCTION The philosophy of knowledge covers a vast and enormously diversified terrain. Within this broad area, the essays that comprise the present book deal specifically with the following issues: 1. The moral dimension of inquiry - in particular, scientific inquiry into the ways of the world (Chapter 1) 2. The epistemic status of such cognitive 'values' of inquiry as - coherence (Chapter 2) - consistency (Chapter 3) - completeness (Chapter 4) 3. The cognitive bearing of probabilistic considerations (Chapters 5 and 6) 4. The epistemic status of certain ideal desiderata of cognition, such as - totality (Chapter 7) - precision (Chapter 8) - exactness (Chapter 9) 5.

The aim of this monograph is to expound the conceptions of temporalized modality at issue in various Arabic logical texts. I claim to have been able to make good logical sense of doctrines of which even the later Arab logicians themselves came to despair. In the process, a substantially new area of the history of logic has come into a clear view. I am indebted to Anne Cross (Mrs. Michael) Pelon and especially Mr. Bas van Fraassen for assistance in the research. Miss Dorothy Henle merits my thanks for preparing the difficult typescript for the printer and helping to see the book through the press. Also, I am grateful to the Editors of Foun dations of Language for inviting inclusion of the monograph in the Supple mentary Series of the journal. The present work is part of a series of studies of Arabic contributions to logic supported by research grants from the National Science Foundation. It affords me much pleasure to record my sincere thanks for this assistance."

The eminent philosopher of science Carl G. Hempel, Stuart Professor of Philosophy at Princeton University and a Past President of the American Philosophical Association, has had a long and distinguished academic career in the course of which he has been professorial mentor to some of America's most distinguished philosophers. This volume gathers together twelve original papers by Hempel's students and associates into a volume intended to do homage to Hempel on the occasion of his 65th year in 1970. The papers are grouped around the unifying topic of Hempel's own interests in logic and philosophy of science, the great majority dealing with issues on inductive logic and the theory of scientific explanatio- problems to which Hempel has devoted the bulk of his outstandingly fruitful efforts. With the approach of 'Peter' Hempel's 65th birthday, an editorial committee sprang into being by an uncannily spontaneous process to prepare to commemorate this event with an appropriate Festschrift. The editors were pleased to receive unfailingly prompt and efficient coopera tion on the part of all contributors. The responsibility of seeing the work through the press was assumed by Nicholas Rescher. The editors are grateful to all concerned for their collaboration. ALAN ROSS ANDERSON PAUL BENACERRAF ADOLF GRUNBAUM GERALD J. MASSEY NICHOLAS RESCHER RICHARD S. RUDNER TABLE OF CONTENTS PREFACE V PAUL OPPENHEIM: Reminiscences of Peter 1 w. v. QUINE: Natural Kinds 5 JAAKKO HINTIKKA: Inductive Independence and the Paradoxes of Confirmation 24 WESLEY c."

The aim of the book is to introduce the reader to some new areas oflogic which have yet to find their way into the bulk of modern logic books written from the more orthodox direction of the mainstream of develop ments. Such a work seems to me much needed, both because of the in trinsic value and increasing prominence of the nonstandard sector of logic, and because this particular sector is of the greatest interest from the standpoint of philosophical implications and applications. This book unites a series of studies in philosophical logic, drawing for the most part on material which I have contributed to the journal liter ature of the subject over the past ten years. Despite the fact that some of these essays have been published in various journals at different times, they possess a high degree of thematic and methodological unity. All of these studies deal with material of substantial current interest in philo sophical logic and embody a fusion of the modern techniques of logical and linguistic-philosophical analysis for the exploration of areas of logic that are of substantial philosophical relevance."

The increasingly lively controversy over scientific realism has become one of the principal themes of recent philosophy. 1 In watching this controversy unfold in the rather technical way currently in vogue, it has seemed to me that it would be useful to view these contemporary disputes against the background of such older epistemological issues as fallibilism, scepticism, relativism, and the traditional realism/idealism debate. This, then, is the object of the present book, which will recon sider the newer concerns about scientific realism in the context of these older philosophical themes. Historically, realism concerns itself with the real existence of things that do not "meet the eye" - with suprasensible entities that lie beyond the reach of human perception. In medieval times, discussions about realism focused upon universals. Recognizing that there are physical objects such as cats and triangular objects and red tomatoes, the medievels debated whether such "abstract objects" as cathood and triangularity and redness also exist by way of having a reality indepen dent of the concretely real things that exhibit them. Three fundamen tally different positions were defended: (1) Nominalism. Abstracta have no independent existence as such: they only "exist" in and through the objects that exhibit them. Only particulars (individual substances) exist. Abstract "objects" are existents in name only, mere thought fictions by whose means we address concrete particular things. (2) Realism. Abstracta have an independent existence as such."

The essays included in this volume are a mixture of old and new. Three of them make their first appearance in print on this occa sion (Nos III, IV, and V). The remaining four are based upon materials previously published in learned journals or anthologies. (However, these previously published papers have been revised and, generally, expanded for inclusion here.) Detailed acknowl edgement of prior publications is made in the notes to the relevant articles. I am grateful to the editors of these several publications for their kind permission to use this material. I am grateful to an anonymous reader for the Western Ontario Series for some useful corrigenda. And I should like to thank John Horty and Lily Knezevich for their help in seeing this material through the press. NICHOLAS RESCHER Pittsburgh, Pennsylvania May, 1980 xi INTRODUCTION The unifying theme of these essays is their concern with Leibniz's metaphysics of nature. In particular, they revolve about his cos mology of creation and his conception of the real world as one among infinitely many equipossible alternatives."

This book is a study in the methodology of philosophical inquiry. Accordingly, it is a venture in metaphilosophy, perhaps the most controversial of philosophical disciplines.

Philosophy is caught in a dilemma. On one hand, its omission as a legitimate venture in empirical inquiry requires its looking to "the big picture" and striving to counteract the fragmented specialization of other cognitive domains. On the other hand, philosophy does not and cannot avert division of labor. Thus, it remains committed to the quest for unity and coherence in our understanding of the nature of things in a world where our knowledge is exploding in scope and in complexity. "

Philosophical Reasoning" explores this difficult situation and clarifies its implications by expounding and defending the following thesis: that systematization is the proper instrument of philosophical inquiry, and that the effective pursuit of philosophy's mission calls for constructing a doctrinal system that answers our questions in a coherent and comprehensive manner.

This book is a study in the methodology of philosophical inquiry. Accordingly, it is a venture in metaphilosophy, perhaps the most controversial of philosophical disciplines.

Philosophy is caught in a dilemma. On one hand, its omission as a legitimate venture in empirical inquiry requires its looking to "the big picture" and striving to counteract the fragmented specialization of other cognitive domains. On the other hand, philosophy does not and cannot avert division of labor. Thus, it remains committed to the quest for unity and coherence in our understanding of the nature of things in a world where our knowledge is exploding in scope and in complexity. "

Philosophical Reasoning" explores this difficult situation and clarifies its implications by expounding and defending the following thesis: that systematization is the proper instrument of philosophical inquiry, and that the effective pursuit of philosophy's mission calls for constructing a doctrinal system that answers our questions in a coherent and comprehensive manner.