XO12 Copulata pulcherrima diuersis ex autoribus logice in vnu[m] corrogata in vetere[m] artem Aresto. cu[m] textu eiusde[m] s[e]c[un]d[u]m via[m] diui doctoris Thome de Aquino & iuxta processu[m] m[a]g[ist]ro[rum] Colonie in bursa Montis rege[n]tiu[m]

Copulata pulcherrima diuersis ex autoribus logice in vnu[m] corrogata in vetere[m] artem Aresto. cu[m] textu eiusde[m] s[e]c[un]d[u]m via[m] diui doctoris Thome de Aquino & iuxta processu[m] m[a]g[ist]ro[rum] Colonie in bursa Montis rege[n]tiu[m] (Cologne: Heinrich Quentell, 1494)

Penn Libraries, Kislak Center for Special Collections, Rare Books and Manuscripts, Folio Inc A-1004

This collective volume contains texts belonging to the so-called “logica vetus” (including the Latin translations of Porphyry’s Isagoge and Aristotle’s Categories and On interpretation by Boethius as well as the Liber sex principiorum attributed to Gilbert de la Porrée). The works are accompanied by the commentary of a professor at the University of Cologne, Lambertus De Monte (d. 1499). This exemplar is notable because of the manuscript illustration on the title page, a scale with several captions in Latin, referring to philosophical concepts: operatio (actuality), potentia (potentiality or faculty), essentia (substance) on the left, and diffinitio (definition), divisio (division), and demonstratio (demonstration) on the right. This was likely a mnemonic device to visualize foundational concepts of Aristotelian philosophy and logic. On the title page, we also find inscribed the names of the book’s previous owners (the Franciscan Observant House in Augsburg and a no better-identified Johannes Telserus).