Because of his "heretical" teachings, which threatened the Catholic Church's power, Galileo was brought before a church court, called the Inquisition. These Inquisitions were infamous for their lack of interest in searching for the truth and their propensity to resort to torture to extract confessions.

Fortunately, Galileo had been so deeply respected for his great mind that he managed to retain some friends in the Catholic Church. Although he could easily have been put into prison, or burned at the stake as many had been before him, his friends convinced the Inquisition to convert his sentence to life imprisonment in his own home.