Opticorum Libri Sex

François d'Aguilon and Theodor Galle after Sir Peter Paul Rubens

National Gallery of Art

Printed in black on now-darkened paper, lines of text are above and below an illustration showing three winged, nude children gesturing toward a balding older, bearded man near the center. The older man sits on a throne to the right and leans forward, one hand braced on the sphinx-shaped arm of the chair and the other pointing toward a stick one of the children holds. One of the man’s eyes is open wide, and the other appears to be closed. The man is barefoot and wears voluminous, flowing robes. The children all have short, curly hair and muscular bodies. Drapery flits to cross the groin of the child closest to us and the back side of another. They all reach at least one hand forward toward the man. The front child holds up the stick and looks over his shoulder at us. The room behind them has a door opening into a cavernous space with arched vaults. The corner of the paneled room beyond the older man has shelves and a ledge with books and globes. The page is numbered 151 in the top right corner. Text above the image reads, in all caps: “Francisci Agvilonii e Societate Iesv Opticorvm Liber Tertivs de Commvnivm Obiectorvm Cognitione.” The block of text under the image is titled “Argvmentvm” in all caps. Text continues, in italics mixed case: “Natvræ simul ac doctrinæ ordo exposcit, vt definite visus essential, præcipua’que eius affectione, quæ ad visionis modum opticorum’que radiorum traductionem pertinent, explicate, ad communium visibilium cognitionem veniamus. Hæc enim per se quidem, at non primò, vt et quæ propria dicuntur, sub aspectum cadunt. Nam lux et color simplici obtutu; hæc verò aut collatione, aut distinction, aut antecedente notione, aut syllogism, aut alia demum ratione, quam internus sensus variam ac multiplicem administrat, cognoscuntur. Quod sane ex eo prouenire videtur, quòd hæc non propriè ad visus facultatem attineant, sed aliis quoque sensibus sese ingerant: vnde N4 non”