Ancient Formal Logic (Studies in Logic and the Foundations of Mathematics, 2)

ANCIENT FORMAL LOGIC

I. M. B O C H E ~ S K I Professor of Philosophy University of Fribourg

1951

N 0 R T H -HO L L A N D P U B L I S H IN G C 0 M P A N Y A M STE R D A M

PRINTED IN THE NETHERLAXDS DRUKKERIJ HOLLAND N.V.. ABISTERDAM

PREFACE Among the great things which the Atlantic World inherited from Greece, the capacity of understanding pure forms is perhaps one of the greatest and Formal Logic is no small part of this capacity. Unfortunately, Greek Formal Logic is all but unknown to modern men, and what is worse, “an up-to-date picture of the history of ancient Logic is at best a hope for the future”. 1 Yet, some of the details of this history can be known. The aim of the present work is to collect some of the data available in the actual state of science and to arrange them in a kind of outline, which would show forth at least some of our indebtedness to Greek Logicians and allow us to see how their results were reached. This book could not have been written without the direct or indirect help of many scholars to whom the author wishes to express his thanks. To Professor J. Lukasiewicz it owes its general spirit and fundamental ideas. The discussions with the late Fr. J. Salamucha helped considerably in the understanding of several Greek doctrines. The works of Professor H. Scholz, Sir W. D. Ross, Professor F. Solmsen, Dr A. Becker and others were freely used. Dr B. Mates was so kind as to lend the manuscript of his excellent dissertation on Stoic Logic. Both Professor E. W. Beth and Professor K. Durr supplied valuable information. Fr. I. Thomas was kind enough to read the manuscript and made many suggestions. It will perhaps be allowed the author to state that when he looks back upon his many years work on the history of logic, he finds that this work would not have been undertaken without the general philosophical background assumed by him. This background is the acknowledgement of the importance of Logic and the high valuation of the so-called “scholastic subtleties”. For l)

Kapp 20.

VI

PREFACE

only one who thinks that reason has some uses might become interested in such specculations as are found in the Prior Analytics or in the Stoic Fragments. This belief is, fortunately, also shared by many philosophers belonging to different schools ; for them the present book may have meaning. For it attempts to show across many centuries a long line of thinkers who thought and worked in a manner essentially still ours.

LIST O F SYMBOLS other than those of the Principia Mathematica $>