and by as few principles as possible.  Beside inert matter, this requires only two active forces, on whose interaction all becoming and all life depend.  These are warmth, which expands, and cold, which contracts; the former resides in the sun and thence proceeds, the latter is situated in the earth.  Although Telesius acknowledges an immaterial, immortal soul, he puts the emphasis on sensuous experience, without which the understanding is incapable of attaining certain knowledge.  He is a sensationalist both in the theory of knowledge and in ethics, holding the functions of judgment and thought deducible from the fundamental power of perception, and considering the virtues different manifestations of the instinct of self-preservation (which he ascribes to matter as well).

[Footnote 1:  Cf. on Telesius, Florentine, 2 vols., Naples, 1872-74; K. Heiland, Erkenntnisslehre und Ethik des Telesius, Doctor’s Dissertation at Leipsic, 1891.  Further, Rixner and Siber, Leben und Lehrmeinungen beruehmter Physiker am Ende des XVI. und am Anfang des XVII.  Jahrhunderts, Sulzbach (1819-26), 7 Hefte, 2d ed., 1829.  Hefte 2-6 discuss Cardanus, Telesius, Patritius, Bruno, and Campanella; the first is devoted to Paracelsus, and the seventh to the older Van Helmont (Joh.  Bapt.).]

With the name of Telesius we usually associate that of Franciscus Patritius (1529-97), professor of the Platonic philosophy in Ferrara and Rome (Discussiones Peripateticae, 1581; Nova de Universis Philosophia, 1591), who, combining Neoplatonic and Telesian principles, holds that the incorporeal or spiritual light emanates from the divine original light, in which all reality is seminally contained; the heavenly or ethereal light from the incorporeal; and the earthly or corporeal, from the heavenly—­while the original light divides into three persons, the One and All (Unomnia), unity or life, and spirit.

The Italian philosophy of nature culminates in Bruno and Campanella, of whom the former, although he is the earlier, appears the more advanced because of his freer attitude toward the Church.  Giordano Bruno was born in 1548 at Nola, and educated at Naples; abandoning his membership in the Dominican Order, he lived, with various changes of residence, in France, England, and Germany.  Returning to his native land, he was arrested in Venice and imprisoned for seven years at Rome, where, on February 17, 1600, he suffered death at the stake, refusing to recant. (The same fate overtook his fellow-countryman, Vanini, in 1619, at Toulouse.) Besides three didactic poems in Latin (Frankfort, 1591), the Italian dialogues, Della Causa, Principio ed Uno, Venice, 1584 (German translation by Lasson, 1872), are of chief importance.  The Italian treatises have been edited by Wagner, Leipsic, 1829, and by De Lagarde, 2 vols., Goettingen, 1888; the Latin appeared at Naples, in 3 vols., 1880, 1886, and 1891.  Of a passionate and imaginative nature, Bruno was not an essentially