ABSTRACT
In this chapter the author discusses with another virtually forgotten system, devised and used by Byzantine Greeks, and imported into Italy in the second half of the fifteenth century. If one looks for the Byzantine visual aids in Zabarella, however, one searches in vain. The geometric diagrams are 'natural' to Greek Byzantine traditions; but the author considers the Greek heritage only in so far as it impinges on their 'Latinization'. The Greek émigrés, George of Trebizond from Crete and Joannes Argyropoulos, were the first to introduce the geometric diagrams in Latin manuals, precisely as aids to teaching young pupils logic. Francesco Barbaro had studied Greek with Guarino Veronese, invited George of Trebizond to Venice, and collected Greek and Latin manuscripts throughout his life. The 1567 vernacular edition of George of Trebizond's Isagoge Dialecticawas the last to be printed in the Renaissance. Toscanella translated his commentary along with George of Trebizond's text.
