[90] theory. In the final examination, he was threatened with torture. He said that before the decree of 1616 he had held the truth of the Copernican system to be arguable, but since then he had held the Ptolemaic to be true. Next day, he publicly abjured the scientific truth which he had demonstrated. He was allowed to retire to the country, on condition that he saw no one. In the last months of his life he wrote to a friend to this effect: “The falsity of the Copernican system cannot be doubted, especially by us Catholics. It is refuted by the irrefragable authority of Scripture. The conjectures of Copernicus and his disciples were all disposed of by the one solid argument: God’s omnipotence can operate in infinitely various ways. If something appears to our observation to happen in one particular way, we must not curtail God’s arm, and sustain a thing in which we may be deceived.” The irony is evident. Rome did not permit the truth about the solar system to be taught till after the middle of the eighteenth century, and Galileo’s books remained on the Index till 1835. The prohibition was fatal to the study of natural science in Italy. The Roman Index reminds us of the significance of the invention of printing in the struggle for freedom of thought, by making [91] it easy to propagate new ideas far and wide. Authority speedily realized the danger, and took measures to place its yoke on the new contrivance, which promised to be such a powerful ally of reason. Pope Alexander VI inaugurated censorship of the Press by his Bull against unlicensed printing (1501). In France King Henry II made printing without official permission punishable by death. In Germany, censorship was introduced in 1529. In England, under Elizabeth, books could not be printed without a license, and printing presses were not allowed except in London, Oxford, and Cambridge; the regulation of the Press was under the authority of the Star Chamber. Nowhere did the Press become really free till the nineteenth century. While the Reformation and the renovated Roman Church meant a reaction against the Renaissance, the vital changes which the Renaissance signified—individualism, a new intellectual attitude to the world, the cultivation of secular knowledge—were permanent and destined to lead, amid the competing intolerances of Catholic and Protestant powers, to the goal of liberty. We shall see how reason and the growth of knowledge undermined the bases of theological authority. At each step in this process, in which philosophical speculation, historical