“I shall deserve the Reputation of having beene ye first to lay the grounds of two Sciences,” wrote Thomas Hobbes in 1646, “this of Optiques … and yt other of natural Justice.” For him, optics and politics were two prongs of the same effort: to naturalize humans’ relations to their world and to each other. It was Descartes’ Dioptrique, handed to him by Digby in 1637, that put Hobbes on his path: naturalizing humans required physicalizing vision and removing from nature all cognitive entities such as “species visible and intelligible.” Hobbes understood that Descartes’ naturalized optics determined that the eye was not the mind’s window to the world, but a mere “darke roome” – a physical camera obscura, receiving “nothing of the Thing” but light rays. Descartes – pace his critics and disciples discussed in the first paper, did have a naturalized theory of the emergence of meaning from causality. It was the passions that mediated mind and world, choosing among the infinity of causal effects those that affect us positively and negatively, and, sanctioned by our very survival as individual and species, serve as foundations of all our knowledge. Hobbes, apparently independently from Descartes, took the same route from “Optiques [to] natural Justice,” basing his political theory on the conviction that “the passions of man … are the beginning of all his voluntary motions.” Benedictus Spinoza, following and out-doing Descartes and Hobbes, based his own effort to naturalize humans on the most radical interpretation of their turn to the passions: “Desire is the essence of Man.”