The Optica Promota and Spinoza’s concept of focus

Spinoza: Against Hyperbolic Vision There are several points of correspondence between Spinoza’s objections to Descartes’ treatment of the magnification of images in the L’Dioptrique in his letters 39 and 40, and the analyses found in James Gregory’s Optica Promota, but perhaps the most significant touching point occurs in Gregory’s conclusion, where he brings up the lone failings of parabolic mirrors [...]

The Optica Promota, by James Gregory (1663)

A valuable Spinoza resource: we have an on-line photocopy edition of the 1663 work Optica Promota by James Gregory, an edition found in Spinoza’s library of books. One can see the imprint that Spinoza likely looked at. This copy is found here. Not only this, Ian Bruce has supplied us with a marvelous English translation and [...]