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 idea of God in us, which can have been derived from no other than an infinite source. It would be impossible for so small a part of the universe as man to produce from himself the idea of a being incomparably greater than the whole universe. I attain a knowledge of God's nature from my own by thinking away from the latter, in which, as in everything finite, being and non-being are intermingled, every limitation and negation, by raising to infinity my positive fundamental powers, _posse, cognoscere_, and _velle_, or _potentia, sapientia_, and _amor_, and by transferring them to him, who is pure affirmation, _ens_ entirely without _non-ens_. Thus I reach as the three pro-principles or primalities of the existent or the Godhead, omnipotence, omniscience, and infinite love. But the infrahuman world may also be judged after the analogy of our fundamental faculties. The universe and all its parts possess souls; there is naught without sensation; consciousness, it is true, is lacking in the lower creatures, but they do not lack life, feeling, and desire, for it is impossible for the animate to come from the inanimate. Everything loves and hates, desires and avoids. Plants are motionless animals, and their roots, mouths. Corporeal motion springs from an obscure, unconscious impulse of self-preservation; the heavenly bodies circle about the sun as the center of sympathy; space itself seeks a content _(horror vacui_).