Italian philosopher, b. at Nola in Campania, in the Kingdom of Naples, in 1548; d. at Rome, 1600. At the age of eleven he went to Naples, to study "humanity, logic, and dialectic", and, four years later, he entered the Order of St. Dominic, giving up his worldly name of Filippo and taking that of Giordano. He made his novitiate at Naples and continued to study there. In 1572 he was ordained a priest.

It seems, however, that, even as a novice, he attracted attention by the originality of his views and by his outspoken criticism of accepted theological doctrines. After his ordination things reached such a pass that, in 1576, formal accusation of heresy was brought against him. Thereupon he went to Rome, but, apparently, did not mend his manner of speaking of the mysteries of faith; for the accusations were renewed against him at the convent of the Minerva. Within a few months of his arrival he fled the city and cast off all allegiance to his order.

From this point on, his life-story is the tale of his wanderings from one country to another and of his failure to find peace anywhere. He tarried awhile in several Italian cities, and in 1579 went to Geneva, where he seems to have adopted the Calvinist faith, although afterwards, before the ecclesiastical tribunal at Venice, he steadfastly denied that he had ever joined the Reformed Church. This much at least is certain; he was excommunicated by the Calvinist Council on account of his disrespectful attitude towards the heads of that Church and was obliged to leave the city. Thence he went to Toulouse, Lyons, and (in 1581) to Paris.

At Lyons he completed his "Clavis Magna", or "Great Key" to the art of remembering. In Paris he published several works which further developed his art of memory-training and revealed the two-fold influence of Raymond Lully and the neo-Platonists. In 1582 he published a characteristic work, "Il candelaio", or "The Torchbearer", a satire in which he exhibits in a marked degree the false taste then in vogue among the humanists, many of whom mistook obscenity for humour. While at Paris he lectured publicly on philosophy, under the auspices, as it seems, of the College of Cambrai, the forerunner of the College of France.

In 1583 he crossed over to England, and, for a time at least, enjoyed the favour of Queen Elizabeth and the friendship of Sir Philip Sidney. To the latter he dedicated the most bitter of his attacks on the Catholic Church, "Il spaccio della bestia trionfante", "The Expulsion of the Triumphant Beast", published in 1584. He visited Oxford, and, on being refused the privilege of lecturing there, he published (1584) his "Cena delle ceneri", or "Ash-Wednesday Supper", in which he attacked the Oxford professors, saying that they knew more about beer than about Greek. In 1585 he returned to France, and during the year which he spent in Paris at this time made several attempts to become reconciled to the Catholic Church, all of which failed because of his refusal to accept the condition imposed, namely, that he should return to his order.

In Germany, whither he went in 1587, he showed the same spirit of insolent self-assertion as at Oxford. In Helmstadt he was excommunicated by the Lutherans. After some time spent in literary activity at Frankfort, he went, in 1591, to Venice at the invitation of Mocenigo, who professed to be interested in his system of memory-training. Failing to obtain from Bruno the secret of his "natural magic", Mocenigo denounced him to the Inquisition. Bruno was arrested, and in his trial before the Venetian inquisitors first took refuge in the principle of "two-fold truth", saying that the errors imputed to him were held by him "as a philosopher, and not as an honest Christian"; later, however, he solemnly abjured all his errors and doubts in the matter of Catholic doctrine and practice (Berti, Docum., XII, 22 and XIII, 45). At this point the Roman Inquisition intervened and requested his extradition. After some hesitation the Venetian authorities agreed, and in February, 1593, Bruno was sent to Rome, and for six years was kept in the prison of the Inquisition. Historians have striven in vain to discover the explanation of this long delay on the part of the Roman authorities. In the spring of 1599, the trial was begun before a commission of the Roman Inquisition, and, after the accused had been granted several terms of respite in which to retract his errors, he was finally condemned (January, 1600), handed over to the secular power (8 February), and burned at the stake in the Campo dei Fiori in Rome (17 February). Bruno was not condemned for his defence of the Copernican system of astronomy, nor for his doctrine of the plurality of inhabited worlds, but for his theological errors, among which were the following: that Christ was not God but merely an unusually skillful magician, that the Holy Ghost is the soul of the world, that the Devil will be saved, etc.

To the works of Bruno already mentioned the following are to be added: "Della causa, principio ed uno"; "Dell' infinito universo e dei mondi"; "De Compendiosâ Architecturâ"; "De Triplici Minimo"; "De Monade, Numero et Figurâ." In these "the Nolan" expounds a system of philosophy in which the principal elements are neo-Platonism, materialistic monism, rational mysticism (after the manner of Raymond Lully), and the naturalistic concept of the unity of the material world (inspired by the Copernican astronomy). His attitude towards Aristotle is best illustrated by his reiterated assertion that the natural philosophy of the Stagirite is vitiated by the predominance of the dialectical over the mathematical mode of conceiving natural phenomena. Towards the Scholastics in general his feeling was one of undisguised contempt; he excepted, however, Albert the Great and St. Thomas, for whom he always maintained a high degree of respect. He wished to reform the Aristotelean philosophy, and yet he was bitterly opposed to his contemporaries, Ramus and Patrizzi, whose efforts were directed towards the same obect. He was acquainted, though only in a superficial way, with the writings of the pre-Socratic philosophers of Greece, and with the works of the neo-Platonists, especially with the books falsely attributed to Iamblichus and Plotinus. From the neo-Platonists he derived the tendency of his thought towards monism. From the pre-Socratic philosophers he borrowed the materialistic interpretation of the One. From the Copernican doctrine, which was attracting so much attention in the century in which he lived, he learned to identify the material One with the visible, infinite, heliocentric universe.

Thus, his system of thought is an incoherent materialistic pantheism. God and the world are one; matter and spirit, body and soul, are two phases of the same substance; the universe is infinite; beyond the visible world there is an infinity of other worlds, each of which is inhabited; this terrestrial globe has a soul; in fact, each and every part of it, mineral as well as plant and animal, is animated; all matter is made up of the same elements (no distinction between terrestrial and celestial matter); all souls are akin (transmigration is, therefore, not impossible). This unitary point of view is Bruno's justification of "natural magic." No doubt, the attempt to establish a scientific continuity among all the phenomena of nature is an important manifestation of the modern spirit, and interesting, especially on account of its appearance at the moment when the medieval point of view was being abandoned. And one can readily understand how Bruno's effort to establish a unitary concept of nature commanded the admiration of such men as Spinoza, Jacobi, and Hegel. On the other hand, the exaggerations, the limitations, and the positive errors of his scientific system; his intolerance of even those who were working for the reforms to which he was devoted; the false analogies, fantastic allegories, and sophistical reasonings into which his emotional fervour often betrayed him have justified, in the eyes of many, Bayle's characterization of him as "the knight-errant of philosophy." His attitude of mind towards religious truth was that of a rationalist. Personally, he failed to feel any of the vital significance of Christianity as a religious system. It was not a Roman Inquisitor, but a Protestant divine, who said of him that he was "a man of great capacity, with infinite knowledge, but not a trace of religion."

The latest edition of Bruno's works is by Tocco, Opere latine di G. B. (Florence, 1889); Opere inedite (Naples, 1891); (Leipzig, 1829, 1830). See also: McIntyre, Giordano Bruno (London and New York, 1903); Frith, Life of G. B. (London and Boston, 1887); Adamson in Development of Modern Philosophy (London, 1903), II, 23-44; Höffding, Hist. of Modern Philosophy, tr. Meyer (London, 1900), I, 110 sqq.; Stöckl, Gesch. der Phil. des Mittelalters (Mainz, 1866), III, 106 sqq.; Turner, Hist. of Phil. (Boston, 1903), 429 sqq.

WILLIAM TURNER