an infinity of unavoidable distractions, had already delayed my work to an exasperating degree. However, it seemed necessary to be realistic, so I carefully read through Ross’s text and commentary. In doing so I found, with some natural regret, that he had anticipated most of the suggestions that I had intended to make. In such cases I hope that I have always yielded him full credit for the improvement. Where his reading or interpretation was different from mine, it was generally better; and I adopted it with proper acknowledgement. There remain a few places in which I still prefer my own view. But I am conscious that I (like all amateur Aristotelians) owe an immense debt to Sir David’s profound scholarship and penetrating criticism, which have opened my eyes to many things that I should otherwise have missed. I must also pay tribute to the Oxford Translation by G. R. G. Mure, which I have often consulted and always found helpful and stimulating. Finally, I am greatly obliged to the late Professor J. Tate for clarifying my mind on some difficult points, and to my colleague Miss N. P. Miller for saving me from many inaccuracies. In spite of these aids I cannot claim to have carried out this task even to my own satisfaction. I should have liked to continue the effort; but it has taken far too long already.The Traditional Mood-Names
In my notes I have frequently had occasion to use the Latin (or quasi-Latin) names invented by medieval logicians to designate the various moods of syllogism. They are as follows:
First figure: Barbara, Celarent, Darii, Ferio.
Second figure: Cesare, Camestres, Festino, Baroco.
Third figure: Darapti, Felapton, Disamis, Datisi, Bocardo, Ferison.
For present purposes this list is sufficient; a fuller one with more detailed information will be found in the introduction to the Prior Analytics. Here it is only necessary to understand that in each name the vowels indicate the quantity and quality of the premisses and conclusion: thus A stands for the universal affirmative (All X is Y), E for the universal negative (No X is Y), I for the particular affirmative (Some X is Y), and 0 for the particular negative (Some X is not Y).