The most widely read logic book in fifteenth-century Italy, Logica Parva was copied in more than 80 manuscripts and 25 editions. By transmitting Oxford logic to Italy it influenced the development of logic, science and philosophy in the Renaissance. This first critical edition from the manuscripts locates the Logica Parva within the tradition of late medieval logic and semantics. The Introduction gives an inventory of all manuscripts of the Logica Parva and an extensive Commentary analyzes the work's key terms and concepts.