Galileo's Non-Trial (1616), Pre-Trial (1632-1633), and Trial (May 10, 1633): A Review of Procedure, Featuring Routine Violations of the Forum of Conscience

Abstract

This article examines Galileo's confrontations with the Holy Office of the Roman Inquisition in light of the rules and technicalities of inquisitorial procedure as set forth in the Corpus juris canonici, officially issued in 1582 under the auspices of Pope Gregory XIII. The primary decretal governing inquisition comes from the Fourth Lateran Council of 1215, which also established the regulations of sacramental confession and the seal of secrecy. Inquisition was intended for the prosecution of public crimes, but when it was adapted to pursuing heresy, the rights of suspects were regularly disregarded, and, rather than being charged with public crimes, they were forced to incriminate themselves, even on secret deeds and previously unuttered beliefs. When first summoned in 1616, Galileo was not questioned, but merely warned not to espouse heliocentrism. In 1632, Holy Office investigations resulted in a summons, and when he appeared in April 1633, he was interrogated without being charged. His formal trial took place on May 10, and his guilty plea of favoring heliocentrism without heretical intention triggered an automatic examination of his private beliefs under torture (in his case, threat of torture), a new procedure adopted by the Holy Office around the turn of the seventeenth century.