Nicolaus Copernicus surviving primary documents on the early years of Copernicus's childhood and education. Copernicus biographers assume that Watzenrode first sent young Copernicus to St. John's School, at Toruń, where he himself had been a master. Later, according to Armitage, the boy attended the Cathedral School at Włocławek, up the Vistula River from Toruń, which prepared pupils for entrance to the University of Kraków, Watzenrode's alma mater in Poland's capital. In the winter semester of 1491–92 Copernicus, as "Nicolaus Nicolai de Thuronia", matriculated together with his brother Andrew at the University of Kraków (now Jagiellonian University). Copernicus began his studies in the
Nicolaus Copernicus Pythagoras's system involved a moving earth. The Pythagorean system was mentioned by Aristotle. Copernicus owned a copy of Giorgio Valla's "De expetendis et fugiendis rebus", which included a translation of Plutarch's reference to Aristarchus's heliostaticism. In Copernicus' dedication of "On the Revolutions" to Pope Paul III—which Copernicus hoped would dampen criticism of his heliocentric theory by "babblers... completely ignorant of [astronomy]"—the book's author wrote that, in rereading all of philosophy, in the pages of Cicero and Plutarch he had found references to those few thinkers who dared to move the Earth "against the traditional opinion of astronomers and almost against