 All this initially reminds us of Descartes; but later in a pessimistic tone, he goes on to say that it is this epistemological uncertainty, this wish to understand (cognitio) “inward ideas” and the impossibility of attaining such knowledge and understanding beyond the senses that drives him to despair. “I see nothing that I could seek to lay hold on, or might possibly grasp” (TNK: 243), he writes in frustration. Then in a moment that recalls Vives’ scepticism (cf. Casini 2009), he ponders: if I am “incapable of comprehending [even] the self” perfectly, how am I “to comprehend the most abstruse secrets of Nature, among which are included spiritual things…?” (TNK: 239). Clearly, argues Sanches, no one doubts that scientific knowledge (scientia) ought to be perfect, but there is nothing, not even in Nature, that is perfect (TNK: 289). And yet this does not lead Sanches to the equanimity or ataraxia (ἀταραξία) of the Stoics. Instead his impassioned scepticism encourages the active search for knowledge. To that end, he ends his treatise with the exhortation: “To work” (TNK: 290) and asks his imaginary interlocutor to teach him what he knows, while he sets to do the double work of examining “Things” while questioning everything that ought to be questioned. Like the Poem of the Comet the treatise’s final word is the interrogative: Quid?/What?