This volume grew out of the papers and comments presented at the Fifth University of Western Ontario Philosophy Colloquium, October 31- November 2, 1969. The colloquium papers were delivered by P. Suppes, R. B. Braithwaite, C. W. Churchman, and J. S. Minas. Comments are provided from others attending the colloquium, with one reply by P. Suppes. Also included are papers recently published elsewhere by A. Michalos, P. Fishburn and H. -N. Castaneda. The editors express thanks to these authors and to the editors of the following respective journals for per- mission to publish: Theory and...

With publication of the present volume, The University of Western Ontario Series in Philosophy of Science enters its second phase. The first fourteen volumes in the Series were produced under the managing editorship of Professor James J. Leach, with the cooperation of a local editorial board. Many of these volumes resulted from colloguia and workshops held in con- nection with the University of Western Ontario Graduate Programme in Philosophy of Science. Throughout its seven year history, the Series has been devoted to publication of high quality work in philosophy of science con- sidered in...

During Hallowe'en of 1970, the Department of Philosophy of the Univer sity of Western Ontario held its annual fall colloquium at London, On tario. The general topic of the sessions that year was conceptual change. The thirteen papers composing this volume stem more or less directly from those meetings; six of them are printed here virtually as delivered, while the remaining seven were subsequently written by invitation. The programme of the colloquium was to have consisted of major papers delivered by Professors Wilfrid Sellars, Stephan Korner, Paul Ziff and Hilary Putnam, with shorter...