Simplicio

Simplicio is a fictional character in Galileo Galilei's Dialogue Concerning the Two Chief World Systems, published in 1632. The Dialogue features three interlocutors: Salviati, Sagredo, and Simplicio. Simplicio serves as the staunch defender of Aristotelian physics and the Ptolemaic geocentric cosmos, arguing from traditional authority and scholastic interpretation rather than empirical observation.

In the text, Simplicio advances the classical view that the Earth is stationary, that the heavens are composed of perfect, unchanging spheres, and that natural philosophy should be governed by established authorities. He tends to rely on deductive reasoning and appeals to tradition, often presenting arguments that are subsequently challenged by Salviati, who represents experimental and observational approaches, and by Sagredo, who acts as a neutral, open-minded participant. The exchanges between Simplicio and the other speakers are used to illustrate the shift from authority-based to evidence-based argument that characterized the scientific revolution.

Legacy and interpretation: Simplicio’s name has entered broader culture as a descriptor for a naive or doctrinaire defender of a theory. In scholarship, he is commonly read as Galileo’s satirical foil aimed at scholastic dogmatism, highlighting the tension between traditional authorities and emerging empirical science. The Dialogue itself contributed to Galileo’s conflict with the Roman Inquisition; while not a direct account of the trial, the work is seen as part of the broader controversy over heliocentrism and the authority of scientific inquiry in early modern Europe.