Thomas Campanella[1] (1568-1639) was no less dependent on Nicolas and Telesius than Bruno. A Calabrian by birth like Telesius, whose writings filled him with aversion to Aristotle, a Dominican like Bruno, he was deprived of his freedom on an unfounded suspicion of conspiracy against the Spanish rule, spent twenty-seven years in prison, and died in Paris after a short period of quiet. Renewing an old idea, Campanella directed attention from the written volume of Scripture to the living book of nature as being also a divine revelation. Theology rests on faith (in theology, Campanella, in accordance with the traditions of his order, follows Thomas Aquinas); philosophy is based on perception, which in its instrumental part comprises mathematics and logic, and in its real part, the doctrine of nature and of morals, while metaphysics treats of the highest presuppositions and the ultimate grounds,—the “pro-principles,” Campanella starts, as Augustine before him and Descartes in later times, from the indisputable certitude of the spirit’s own existence, from which he rises to the certitude of God’s existence. On this first certain truth of my own existence there follow three others: my nature consists in the three functions of power, knowledge, and volition; I am finite and limited, might, wisdom, and love are in man constantly intermingled with their opposites, weakness, foolishness, and hate; my power, knowledge, and volition do not extend beyond the present. The being of God follows from the