A rare 17th century manuscript book on the subject of logic and human intellect. Contemporary limp vellum binding (19cm x 14cm x 3xm), c. 180 leaves of Latin script - entirely manuscript in black ink on quality paper by an accomplished single hand, evidently complete, in single column, chapter headings and endings in bold, hand-drawn illustrations, tables and charts, some pages numbered. Condition: FAIR to GOOD. Covers somewhat cockled and stained. Some very occasional old marginalia. Light staining to final few leaves. Moderate marks throughout.