The present handbook is an exposition and defence of the basic theory of late medieval logic. Paulus Venetus (1370-1429) composed the work soon after he returned from studying in Oxford and Paris at the start of the 15th century. Copied in over 80 manuscript and later published in more than 25 editions it became the leading textbook of its day and earned for its author the reputation of having brought the "Oxonian dialect" to Italy. Its influence extended well beyond Scholasticism. Humanists such as Lorenzo Valla and Marsilio Ficino having learned their logic from it. Thomas More had in mind when he referred to the "Little Logicals". And Juan Luis Vives cites it explicitly in his attacks on Scholasticism. The work consists of eight chapters: the first six - on terms (termini), supposition (suppositio), inference (consequentia), proof (probatio), obligations (obligationes) and insolubles (insolubilia) - set forth the rules of medieval logic and dialectic. In a remarkable these very rules, the last two chapters alternatively attack and defend the most important doctrines of the earlier chapters. With respect to the issues in language and logic today, the work exemplifies late medieval approaches to logical form in its syntactical, semantical, and pragmatic dimensions. The present introductory study shows even more clearly how these contributions relate to present-day work in rational grammar and the theory of logical form. Of interest to: Logicians, linguists, philosophers, theologians and the historians of t disciplines as well as scholars in medieval and renaissance studies