Francisco Sánchez

Born on July 25, 1550, in Tui, Galicia, and raised in Braga, Portugal, Francisco Sanches went on to study and teach medicine, eventually building his career in Toulouse, France. He lived during the Renaissance, when scholars were rethinking old ideas and testing how knowledge should be built.

Sanches is most famous for his 1581 book Quod nihil scitur (That Nothing Is Known), a work that questions whether human beings can ever reach true certainty. Rather than accepting inherited authority at face value, he pushed readers to examine evidence and the limits of reason for themselves.

Alongside philosophy, he was also a practicing physician and a university teacher. That mix of medicine and skeptical inquiry gives his work a distinctive character: curious, sharp, and deeply interested in how people know what they think they know.