Account of a Heretic: Galileo Galilei.
Thomas Aquinas defined heresy as, "a species of infidelity in men who, having professed the faith of Christ, corrupt its dogmas". The Catholic Church of the Middle Ages and Renaissance expanded on this definition and established specific attributes of heresy. The Inquisition of the Catholic Church followed a rubric of requirements those brought before had to meet in order to be considered heretics. A person was not only condemned as a heretic but also labeled with a degree of heresy based on a stratified system. Inquisitors looked for evidence of heterodoxy, notoriety, marginality, and obstinacy when condemning a heretic. The Inquisition's rulings were often unfair and founded on faulty or skewed evidence. Many of the famous condemned heretics were exempt by the Church after their deaths. One such case was Galileo Galilei. Though he died in 1642 still deemed as a heretic, it was not until 1992 that Pope John Paul II admitted Galileo's trial was erroneous. .
In 1543 Copernicus's On the Revolution of the Heavenly Spheres was published after some delay. This piece of scientific literature argued a heliocentric universe. It was a revolutionary idea that contradicted the commonly accepted church teachings but lacked substantial evidence and therefore went unnoticed until many years later. .
Galileo Galilei was born in 1564 in Pisa, Italy. When he turned ten, Galileo moved to Florence where he also received his first schooling from Camaldolese monks. Galileo was so pleased with the monastic life, he wanted to join the order. Upon hearing of this, his father sent Galileo back to Pisa where he would study medicine. By 1585 Galileo left the University of Pisa to pursue his true interests: mathematics. In 1589, after a few years of working on centers of mass, Galileo became the chair of mathematics at the University of Pisa, though he did not hold any formal degrees.