Cartesian schemes. But it took fully fifty years and more, besides, before these ideas had won general acceptance by the common people, so wedded were they to the traditional view through custom and a superstitious reverence for the Bible. Briefly then, the De Revolutionibus appeared in 1543; and quietly won some supporters, notably Bruno, Kepler and Galileo; the Congregations of the Index specifically opposed it in 1616 and 1633; however it continued to spread among scholars and others with the aid of Cartesianism for another fifty years till the appearance of Newton's Principia in 1687. Then its acceptance rapidly became general even in Catholic Europe, till it was almost a commonplace in England by 1743, two hundred years after its first formal promulgation, and had become strong enough in Europe to cause the Congregations in 1757 to modify their stand. Thereafter opposition became a curiosity rather than a significant fact. Only the Roman Church officially delayed its recognition of the new astronomy till the absurdity of its obsolete position was brought home to it by Canon Settele's appeal in 1820. Fifteen years later the last trace of official condemnation was removed, a little over two hundred years after the decrees had first been issued, and just before Bessel's discovery of stellar parallax at length answered one of the strongest and oldest arguments against the system. Since then have come many apologias in explanation and extenuation of the Church's decided stand in this matter for so many generations.
Though Galileo himself was forced to his knees, unable to withstand his antagonists, his work lived on after him; he and Copernicus, together with Kepler and Newton stand out both as scientists and as leaders in the advance of intellectual enlightenment. The account of their work and that of their less well-known supporters, compared with that of their antagonists, proves the truth of the ancient Greek saying which Rheticus used as the motto for the Narratio Prima, the first widely known account of the Copernican system: "One who intends to philosophize must be free in mind."
