As remarked, more than three quarters of a century—that is to say, from the period of the Widmanstadt lecture to the discovery of the satellites of Jupiter—the new theory as propounded by Copernicus was publicly taught or discussed by numbers of the first scholars and men of science in Europe.
Among them were Erasmus, Reinhold, and George Joachim Rheticus; personal friends and survivors of Copernicus.
Francis Patricias, the distinguished Platonist, who from 1592 to 1597 taught the diurnal motion of the earth at Rome under the patronage of the pope. In connection with the name of Patricius it is interesting to note the fact that the most careful biographers of Galileo have been unable to fix the precise time when he abandoned the Ptolemaic system for that of Copernicus. True, M. Libri, (in his Histoire des Sciences Mathématiques en Italie,) with his usual readiness undertakes to inform us, by stating that "Dès sa première jeunesse Galilée avait adopté le système de Copernic," which statement, in a question of dates, we find eminently unsatisfactory. The weight of authority, however, appears to place it somewhere between 1593 and 1597, precisely the period when Patricius was lecturing at Rome.
Christian Urstisius, who died in 1588, publicly taught the theory of Copernicus in a course of lectures delivered in Italy, and to him also is ascribed, by some, the conversion of Galileo to Copernicanism.
Diego or Didacus a Stunica, a Spaniard, a decided Copernican, the first it is said who discussed the Bible arguments, quoting Job: "Who shaketh the earth out of her place, and the pillars thereof tremble."
Peter Ramus, who began his philosophical career by a public attack on the authority of Aristotle, in offering to maintain the contrary of any assertion of his whatever. It is noted as a curious coincidence that the publication of the opinions of Copernicus and of Ramus, controverting ancient astronomy (Ptolemy) and ancient logic, (Aristotle,) were made in the same year, (1543.) Although called by Bacon "a skulking-hole of ignorance," a "pernicious book-worm," etc., he was nevertheless a man of great powers and acquirements. Before Galileo came on the stage, he appeared to favor the system of Copernicus.
Christopher Rothman, who, although a friend and at one time a follower of Tycho Brahe, was a defender both of the annual and diurnal motion of the earth.
William Gilbert and Edward Wright, two English scientific men, who may be classed among the opponents of the Copernican system.
Benedetti, who cautiously favored the system.
Christopher Clavius, a celebrated Jesuit, whose vast learning was the admiration of his age. In 1570, he spoke of Copernicus as the excellent restorer of astronomy whom all posterity will gratefully celebrate and admire as a second Ptolemy. We shall meet Clavius again.