Francisco Sanches

Francisco Sanches was a Hispano-Portuguese skeptic, philosopher and physician of Sephardi Jewish origin, born around 1550, possibly in Tui in Spain or more probably in Braga in Portugal, where he was baptized and grew up, and dying on 16 November 1623. His father Antonio Sanches was a Spanish physician and his mother Filipa de Sousa was Portuguese, and as a converted Jew he was legally a New Christian. Around the age of twelve he moved with his parents to Bordeaux, fleeing the Portuguese Inquisition, and studied at the College de Guyenne, then studied medicine in Rome in 1569 and later in Montpellier and Toulouse, and after 1575 he became professor of philosophy and medicine at the University of Toulouse. In Quod nihil scitur, written in 1576 and published in 1581, he used the classical skeptical arguments to show that science in the Aristotelian sense of necessary causes cannot be attained, because the search for causes falls into infinite regress and syllogisms are circular. He drew on his medical experience to show how unreliable sense experience is, yet concluded that we should still seek the limited, imperfect knowledge that observation, experience and judgment allow, an early form of mitigated skepticism later developed by Marin Mersenne, Pierre Gassendi and the leaders of the Royal Society.