Medieval Logic: An Outline of Its Development from 1250 to ca. 1400 by Philotheus Boehner, O. F. M., and: De Puritate Artis Logicae by Walter Burleigh (review)

258 BOOK REVIEWS Medieval Logic: An Outline of Its Development from 11250 to ca. 1400. By PHILOTHEUS BoEHNER, 0. F. M. Chicago: University of Chicago Press, 195~. Pp. 148. $3.00. De Puritate Artis Logicae. By WALTER BuRLEIGH. Edited by Philotheus Boehner, 0. F. M. St. Bonaventure: The Franciscan Institute and Louvain: E. Nauwelaerts, 1951. Pp. 131. $1.50. The first work is a booklet designed to promote harmony and understanding between scholastic and modern logicians. It is the author's contention that many modern scholastics do not have a genuinely scholastic logic since they do not consider logic as an essentially formal science. And the reason for this is that they are not acquainted with their own tradition, namely, genuine scholastic logic of the 13th, 14th and 15th centuries wherein there is found a logic containing many elements of a strictly formal logic, so much so, that these elements appear to be definite anticipations, if not the exact doctrines, of modern logic. Avoiding the vague phrases, "traditional logic" and "classical logic," Fr. Boehner indicates precisely what he means by " nco-scholastic logic," " Aristotelian logic " and " modem logic," before stating and substantiating his conclusions. This is done in the Introduction. The body of the work is divided into three parts; Part One: Elements of Scholastic Logic; Part Two: Important Contributions of Scholastic Logic; and Part Three: Systems of Scholastic Logic. Part One is divided into two chapters: I, The Legacy of Scholastic Logic, and II, New Elements of Scholastic Logic. For the legacy of scholastic logic he has chosen Albert the Great's logical works as his source. There are eleven works cited, paraphrases on the six works of the Organon plus paraphrases on Boethius's works on division, categorical syllogisms, and hypothetical syllogisms. The other two works are Albert's treatment of the material found in Porphyry's Isagoge and Gilbert de la Poree's Six Principles. These works are merely listed and summarily described with regard to their contents. The new elements which Fr. Boehner lists in chapter two are the small tracts added by later scholastics which he divides into five groups: 1. De Syncategorematibus, ~- De proprietatibus terminorum , 3. De insolubili, 4. De obligatione, 5. De consequentiis. Part Two contains three chapters: I, The Syncategoremata As Logical Constants; II, The Theory of Supposition; and III, The Theory of Consequences . In the first chapter. Fr. Boehner indicates clearly the distinction between categorematic and syncategorematic words and the significative and suppositional dependence of the latter upon the former. He sees in this distinction a definite parallelism with the modern distinction between the constants and variables of logical discourse. A splendid quotation from Albert of Saxony shows that the latter considered the syncategoremata as formal elements which do not change. This is another indication of the BOOK REVIEWS ~59 formalized· character of medieval logic. In the second chapter Fr. Boehner briefly schematizes the theories of Peter of Spain, William Ockham, and Walter Burleigh on supposition. He likens the theory of supposition to the modern functional calculus. In chapter three the author treats of the notion and division of consequences according to William Ockham and Albert of Saxony. He also gives a brief survey of the consequential rules found in Ockham which have corresponding theorems of the propositional calculus. He gives the rule in translation, followed by the Latin text; then he explains and gives an instance of the rule; finally, he places it in symbolization. Part Three contains only one chapter in which the author merely indicates the content of five medieval logicians' works by schematizing a division of their most important logical opus. The five logicians summarized in this manner are Peter of Spain, William Ockham, John Buridan, Walter Burleigh, and Albert of Saxony. Two appendices contain a few sophismata of Albert of Saxony as well as a major portion of his rules of supposition. The second work is believed to be the first edited text of the shorter of two texts bearing the name De Puritate Artis Logicae. It contains Burleigh 's treatment of the general rules of consequences and a much longer discussion (eighty per cent of the text) on the syncategoremata. The publication of this text...