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Bruno, Giordano

Bruno, Giordano

(b. Nola, Italy, 1548; d. Rome, Italy, 17 February 1600)


Bruno’s baptismal name was Filippo; he took the name Giordano, by which he is always known, on entering the Dominican order. His father, Giovanni, was a soldier, and probably a man of fairly good position; his mother, Fraulissa Savolino, has been conjectured to have been of German descent, although there is no real evidence. Hardly anything is known of Bruno’s early years in Nola, a small town near Naples.

At the age of fifteen, Bruno entered the Dominican order and became an inmate of the great Dominican convent in Naples. Here he acquired a grounding in Scholastic philosophy and the reverence for Thomas Aquinas (who had lived and taught in the Naples convent) that he professed throughout his life. Here, too, he became proficient in the art of memory, for which the Dominicans were noted, and was taken to Rome to display his mnemonic skill to Pope Pius V. Another influence which he may have come under in these early years was that of the famous natural magician and scientist Giambattista della Porta, who in 1560 had established in Naples his academy for investigating the secrets of nature. Bruno was formed during these years in Naples: his mind and character never lost the imprint of his training as a friar; and it was as a passionate ex-friar that he wandered over Europe, combining philosophical speculation with a religious mission evolved through deep immersion in Renaissance magic and its Hermetic sources.

Bruno’s religion was the moving force behind both his wandering career and his philosophical and cosmic speculations. He believed that he was reviving the magical religion of the ancient Egyptians, a religion older than Judaism or Christianity, which these inferior religions had suppressed but of which he prophesied the imminent return. It included a belief in the magical animation of all nature, which the magus could learn how to tap and to use, and a belief in metempsychosis. The historical origins of Bruno’s “Egyptianism” and the printed sources whence he derived it are now clear, owing to the work done by scholars in fairly recent years on the Hermetic core of Renaissance Neoplatonism.

As propagated by Marsilio Ficino, Renaissance Neoplatonism included a firm belief that both Plato and his followers had been inspired by a tradition of prisca theologia, or pristine and pure theology, which had come down to them from the teachings of Hermes Trismegistus, a mythical Egyptian sage, and other figures supposedly of extreme antiquity. This belief rested on the misdating of certain late antique texts, of which the most important were the Asclepius and the Corpus Hermeticum, which were supposed to have been written by Hermes Trismegistus himself.

Ficino believed that these texts contained authentic revelations about ancient Egyptian religion and that in them their supposed author prophesied the coming of Christianity—and, hence, could take on sanctity as a Gentile prophet. The scraps of Platonic notions incorporated by the late antique Gnostic writers of the Hermetic texts were, for Ficino, evidence that these ancient “Egyptian” teachings were the pristine source at which Plato and the Neoplatonists had drunk. These beliefs could be supported from works of some Church Fathers, notably Lactantius. Nor were they peculiar to Ficino; on the contrary, the whole Renaissance Neoplatonic movement contained this Hermetic core, and the religious magic, or theurgy, taught by Hermes Trismegistus, particularly in the Asclepius, seemed corroborated by the intensive Renaissance study of the later Neoplatonists, such as Porphyry and Iamblichus. As a pious Christian, Ficino was encouraged by the sanctity of Hermes Trismegistus as a Gentile prophet to embark on the astral magic described in the Asclepius, which lies behind his own work on astral magic, the De vita coelitus comparanda, although he did this hesitantly and timidly, in fear of the Church’s embargo on magic.

The extreme boldness and fearlessness that characterized Giordano Bruno are nowhere more apparent than in his choice of a religion. Discarding the belief in Hermes as a Gentile prophet, which sanctified the Hermetic writings for pious Christian Neoplatonists, Bruno accepted the pseudo-Egyptian religion described in the Hermetic texts as the true religion; he interpreted the lament in the Asclepius over the decay of Egypt and her magical worship as a lament for the true Egyptian religion, which had been suppressed by Christianity, although various signs and portents were announcing its return.

Among these signs was the heliocentricity announced by Copernicus—and it must be confessed that Copernicus himself did something to encourage such an interpretation of his discovery when, at a crucial point in his work, just after the diagram showing the new sun-centered system, he referred to Hermes Trismegistus on the sun as a visible god (a quotation from the Asclepius). In his defense of Copernicanism against the Aristotelians of Oxford, Bruno presented Copernicus as “only a mathematician” who had not understood the true inwardness of his discovery as he, Bruno, understood it—as portending a return to magical insight into living nature. In support of the movement of the earth, Bruno quoted a passage from one of the treatises of the Corpus Hermeticum, which states that the earth moves because it is alive.

The magical animism that permeates Bruno’s philosophy of nature, his vision of the living earth moving round the sun, of an infinite universe of innumerable worlds moving like great animals in space, is inseparably connected with his pseudo-Egyptian religion. It is universal animism which makes possible the activities of the magus and justifies the techniques by which he attempts to operate on nature. Bruno aspired to become such a magus, using the techniques described in the De occulta philosophia of Henry Cornelius Agrippa von Nettesheim, a work that was itself the product of the Hermetic core within Renaissance Neoplatonism.

It is one of the most extraordinary features of Bruno’s outlook that he seems to have believed that his religion could somehow be incorporated within a Catholic framework in the coming new dispensation. He never lost his respect for Thomas Aquinas, and his preaching of his new religion retained traces of Dominican preacher’s training. Although Christ was for him a benevolent magus, as were Thomas Aquinas, Paracelsus, Ramón Lull, and Giordano Bruno himself, he proclaimed in the Spaccio della bestia trionfante that Christ was to remain in heaven as an example of a good life.

While still in the convent in Naples, he fell under suspicion of heresy and proceedings were instituted against him. The suspicion against him seems to have been of Arian tendencies; possibly his full “Egyptian” program was not yet developed. To avoid the process against him he left Naples in 1576. He went first to Rome, where he fell into new difficulties, from which he escaped by abandoning the Dominican habit and fleeing from Italy. Now began his long odyssey through France, England, Germany. He went first to Geneva, where he soon got into trouble and acquired a strong dislike of Calvinism.

From about 1579 to 1581 he was in Toulouse, where he lectured in the university on, among other things, the sphere of Sacrobosco. From Toulouse he went to Paris; here his public lectures attracted the attention of King Henry III. His first published work, the De umbris idearum (Paris, 1582), is dedicated to Henry. It is an example of his transformation of the art of memory into a deeply magical art, and its title is taken from that of a magical book mentioned in the necromantic commentary on the Sphere of Sacrobosco by Cecco d’Ascoli, an author whom Bruno greatly admired. Bruno thus came before the world in his first Parisian period as a magician teaching some extremely abstruse art of memory that apparently gained the interest and approval of the king of France, who gave him letters of recommendation to the French ambassador in England. This is the first indication of some mysterious political, or politicoreligious, undercurrent in Bruno’s activities and movements.

Bruno crossed the Channel to England early in 1583; the royal letters of recommendation had the desired effect, for the French ambassador, Michel de Mauvissière received him into the French embassy, where during the two years of his stay in England he lived as a “gentleman” attached to the embassy. He states that he often accompanied the ambassador to court and saw Queen Elizabeth, whom he addresses as “divine” in his works, an epithet that he had to try to explain away to the Inquisitors. The ambassadorial protection enabled Bruno to publish his extremely provocative works, in which he criticized Reformation Oxford as inferior in philosophical learning to the Oxford of the Middle Ages and attacked the whole social order of Elizabethan England for having destroyed, without adequately replacing, the institutions of Catholic times. His books were published clandestinely, with false imprints, by John Charlewood. As was to be expected, they aroused tumults against the bold ex-friar that were sometimes so violent that he dared not go outside the embassy.

Bruno opened his campaign in England with one of his obscure works on the magic art of memory, the Triginta sigilli; hidden away at the end of it there is a passionate advocacy of a new religion based on love, art, magic, and mathesis; it begins with an abusive dedication to the vice—chancellor and doctors of Oxford. This would seem to have been a strange preparation for his visit to Oxford in the train of the Polish prince, Albert Laski. A newly discovered source, first published in 1960, has thrown much light on Bruno’s famous advocacy of the Copernican theory to the recalcitrant Aristotelians of Oxford. It appears that after Laski’s party had left, Bruno returned to Oxford and delivered lectures that consisted mainly of quotation from Ficino’s book on astral magic, De vita coelitus comparanda, with which he associated the opinion of Copernicus “that the earth did go round and the heavens did stand still.” Bruno’s unacknowledged quotations from Ficino were detected by some of his auditors, as is recounted in the newly discovered report of his speech. This new information about Bruno’s Oxford lectures is external confirmation of what can also be clearly deduced from his works; that for Bruno, Copernican heliocentricity was associated with his magical and animist view of nature.

The brilliant dialogues in Italian that Bruno published while in England have been the most widely read of his works and were the main foundation for his reputation as a bold philosopher breaking out of the closed medieval universe into a new vision of the cosmos. This reputation is by no means undeserved, although it now has to be formulated in more accurate historical terms than those used by his nineteenth-century admirers, who were unaware that their hero was a magician and knew nothing of the complex political and religious situation in Elizabethan England, the scene of these exploits. In the Cena de le ceneri (1584) he defends Copernican heliocentricity against two Oxford “pedants” The angry protests that this attack aroused are described in De la causa, principio e uno (1584); Bruno here offers a slight apology for his attack on Oxford—but in the form of professing admiration for the friars of pre-Reformation Oxford, with whom he unfavorably compares their Protestant successors. This can have done little to improve the situation, and the censor can have been prevented from taking action against the book only because it was dedicated to the French ambassador. In the De l’infinito, universo e mondi (1584), Bruno sets forth his remarkable vision of an infinite universe and innumerable worlds infused with divine life.

In the Spaccio della bestia trionfante (1584), he turns to the moral, as apart from the physical or philosophical, side of his message, and outlines a universal moral and religious reform. The curious form of this work, which is based on the constellations from which vices are said to be expelled, to be replaced by virtues, is related to Bruno’s adaptations of the art of memory. The Cabala del cavallo Pegaseo (1585) is an obscure discussion of the Jewish cabala. In the De gli eroici furori (1585), Bruno expresses himself in a sequence of beautiful poems followed by commentaries explaining their philosophic and mystical meanings. This book is dedicated to Philip Sidney, as is the Spaccio della bestia trionfante. All the other Italian dialogues, with the exception of the Cabala del cavallo Pegaseo, are dedicated to the French ambassador. One is left wondering how far the extraordinary philosophical, magical, and religious views that Bruno propagated from the safety of the French embassy were acceptable to the distinguished persons to whom he dedicated these books. They are all full of Hermetic influences and are bound up with the complex religious, or politico-religious, mission for which he seems to have believed that he had the support of the king of France and to which the French ambassador seems to have lent his protection.

Meanwhile, in France the Catholic League was rising in power; Henry III’s position grew precarious; Mauvissière, the liberal ambassador, was recalled, and late in 1585 Bruno returned to Paris in his train. Immediately he began to talk and to publish, expounding his philosophy in an address delivered by a disciple in the Collège de Cambrai, which was tumultuously received. The king’s support was indirectly withdrawn; and Bruno made himself notorious in a quarrel about a compass with Fabrizio Mordente, which may have had a political background. Paris became too dangerous for him, and in 1586 he fled, this time toward Germany.

At Wittenberg he felt happy for a time: the university allowed him to lecture, and he found that he greatly preferred German Lutherans to English Calvinists. Here he wrote a number of works, particularly on Lullism, which he believed that he understood better than Lull himself. But eventually here also trouble started, and after delivering a moving farewell oration to the doctors of Wittenberg, he went on to Prague, where he dedicated to Emperor Rudolph II his Articuli adversus mathematicos (1588), in which he professed to be strongly against mathematics. This book is illustrated with magical diagrams. In the Preface he urges the emperor to lead a movement of religious toleration and philanthropy. Yet even Rudolph, who collected strange people at his court, did not extend a warm welcome to Bruno; he gave him a little money, but no position, and Bruno wandered on to Helmstedt. Here he found support from Henry Julius of Brunswick-Wolfenbüttel, who may have been in sympathy with his ideas; at any rate, he allowed Bruno to deliver an oration on his recently deceased father which echoed the moral and religious program of the Spaccio della bestia trionfante. While at Helmstedt, Bruno was busily writing; the De magia and other works on magic preserved in the Noroff manuscript may have been written during this period. Henry Julius possibly gave him money toward the publication of the Latin poems that he had been writing during his travels; and Bruno went on to Frankfurt to supervise their printing.

The De immenso et innumerabilibus, the De triplici minimo et mensura, and the De monade numero et figura were published in 1591. In these poems, written in a style imitating that of Lucretius, Bruno expounded for the last time his philosophical and cosmological meditations, mingled, as in the works published in England, with powerful Hermetic influences. His last published work, also published in 1591 by Wechel at Frankfurt, was a book on the magic art of memory dedicated to the alchemist and magician Johannes Hainzell.

While at Frankfurt, Bruno received, through an Italian bookseller who came to the Frankfurt fair, an invitation from Zuan Mocenigo, a Venetian nobleman, to come to Venice and teach him the secrets of his art of memory. He accepted, and in August 1591, he returned to Italy, going first to Padua and then to Venice. There can be little doubt that Bruno believed, like many others at the time, that the conversion of Henry IV of France was a sign of vast impending religious changes in Rome, and that he and his mysterious mission would be well received in the approaching new dispensation. That he had no idea that he was running into danger is shown by the curious fact that he took with him the manuscript of a book that he intended to dedicate to Pope Clement VIII.

Bruno’s reception in Italy was tragically other than he had expected. Mocenigo informed against him, and he was arrested and incarcerated in the prisons of the Inquisition in Venice. There followed a long trial, at the end of which Bruno recanted his heresies and threw himself on the mercy of the inquisitors. He had to be sent on to Rome for another trial, however, and there his case dragged on for eight years of imprisonment and interrogation. After some wavering, he finally refused to recant any of his views, with the result that he was burned alive as a dangerous heretic on the Campo de’ Fiori in Rome.

The grounds on which Bruno was sentenced are unknown, for the processo, or official document containing the sentence, is irretrievably lost. It formed part of a mass of archives that were transported, by order of Napoleon, from Rome to Paris, where they were pulped. From the reports of the interrogations, it is, however, possible to form an idea of the drift of the case against him. To his major theological heresy, the denial of the divinity of the Second Person of the Trinity, was added suspicion of diabolical magical practices. It was probably mainly as a magician that Bruno was burned, and as the propagator throughout Europe of some mysterious magicoreligious movement. This movement may have been in the nature of a secret Hermetic sect, and may be connected with the origins of Rosicrucianism or of Freemasonry. If any philosophical or cosmological points were included in his condemnation, these would have been inextricably bound up with his “Egyptianism.”

The legend that the nineteenth century built around Bruno as the hero who, unlike Galileo, refused to retract his belief that the earth moves is entirely without foundation. Bruno’s case may, however, have affected the attitude of the Church toward the Copernican hypothesis and may have encouraged the Inquisition’s suspicion of Galileo. Although Galileo accepted the Copernican world view on entirely different grounds from Bruno, there are curious formal resemblances between his Dialogo dei due massime sistemi del mondo, in which the pedantic Simplicius takes the Aristotelian side, and Bruno’s Cena de le ceneri, in which the Oxford pedants oppose the “new philosophy.”

The history of Bruno’s reputation is instructive. Abhorred by Marin Mersenne as an impious deist, he was more favorably mentioned by Kepler. Rumors of his diabolism seem to have been circulated, and were mentioned even by Pierre Bayle in one of the footnotes to his contemptuous article on Bruno. The eighteenth-century deist John Toland revived interest in some of his works. It was not until about the mid-nineteenth century that a revival on a large scale began to gather strength and the legend of the martyr for modern science was invented—of the man who died, not for any religious belief, but solely for his acceptance of the Copernican theory and his bold vision of an infinite universe and innumerable worlds. Statues in his honor proliferated in Italy; the literature on him became immense.

In the late nineteenth and early twentieth centuries, Giordano Bruno was one of the most widely known, and most frequently written about, philosophers of the Italian Renaissance. His ideas, isolated from their historical context, were interpreted in terms of the then dominant type of history of philosophy, for example, by Giovanni Gentile, and the large areas in his writings that are not intelligible in terms of straight philosophical thinking were neglected or ignored. Leo Olschki was probably one of the first to notice that no coherent philosophical system could be drawn from Bruno’s works through this approach; and Antonio Corsano emphasized the magical ingredients in Bruno’s thought and the politico-religious aspects of his activities. It is, however, the work that has been done in recent years on the Renaissance Hermetic tradition that has at last made it possible to place Bruno within a context in which his philosophy, his magic, and his religion can all be seen as belonging to an outlook that, however strange, makes historical sense.

Now that Giordano Bruno has been, as it were, found out as a Hermetic magician of a most extreme type, is he therefore to be rejected as of no serious importance in the history of thought? This is not the right way to pose the question. Rather, it should be recognized that Renaissance magic, and that turning toward the world as a revelation of the divine that is the motive force in the “religion of the world” that inspired Bruno, was itself a preparation or a stage in the great movement that, running out of the Renaissance into the seventeenth century, gradually shed its irrational characteristics for the genuinely scientific approach to the world. Bruno’s leap upward through the spheres into an infinite universe, although it is to be interpreted as the experience of a Gnostic magician, was at the same time an exercise of speculative imagination presaging the advent of new world views. Although Bruno infused the innumerable worlds of which he had learned from Lucretius with magical animism, this was in itself a remarkable vision of a vastly extended universe through which ran one law. We can accept Bruno’s Renaissance vision as prophetic of coming world views, although formulated within a very strange frame of reference.

Again, Bruno’s atomism, derived from his study of Lucretius through magical interpretation of Lucretius in such a writer as Palingenius, whose Zodiacus vitae was one of Bruno’s inspirations, may have stimulated the attention of other thinkers. The Renaissance interpretation of Lucretius, which was begun by Ficino, is a stage in the history of atomism which has not yet been adequately examined. When that history comes to be written, Bruno’s magically animated atoms may be found to hold some transitional place in it.

Another example of Bruno’s thought as a presage of scientific discovery is his remarkable intuition about the circular movement of the blood, which he based on parallelism between man and the universe; he believed that “spirit” is the driving force that moves the blood, the same spirit that is diffused through the universe and that Plato defined as “number which moves in a circle.” Hence, the movement of the blood within the body, said Bruno, is circular, diffused from the heart in a circular movement.

One of the closest connections between Bruno and a seventeenth-century scientific philosopher is that which can be discerned in the influence of Bruno’s Cena de le ceneri on William Gilbert’s De magnete. The magnet is always mentioned in textbooks on magic as an example of the occult sympathies in action; and Bruno, when defending his animistic version of heliocentricity, brought in the magnet. Gilbert’s language when defending heliocentricity in the De magnete is extremely close to that of Bruno; like Bruno, he cites Hermes and others who stated that there is a universal life in nature when he is arguing in favor of earth movement. The magnetic philosophy that Gilbert extended to the whole universe seems most closely allied to that of Bruno, and it is not surprising that Francis Bacon should have listed Gilbert with Bruno as proud and fantastic magi of whom he strongly disapproved.

Even the strangest and most formidably obscure of Bruno’s works, those on his magic arts of memory, can be seen to presage, on the Hermetic plane, seventeenth-century strivings after method. Bruno aimed at arranging magically activated images of the stars in memory in such a way as to draw magical powers into the psyche. These systems were of an incredible complexity, involving combinations of memory images with the revolving wheels of Lull to form ways of grasping everything in the universe at once and in all possible combinations. Bruno’s Hermetic computers, if one may be permitted to call them such, were almost certainly known to Leibniz, who was also familiar with the art of memory and with Lullism. When introducing his universal calculus, Leibniz uses language that is remarkably similar to that in which Bruno introduced his art of memory to the doctors of Oxford. The many curious connections between Bruno and Leibniz may, when fully explored, form one of the best means of watching the transitions from Renaissance occultism to seventeenth-century science.

Within that view of the history of thought in which the Renaissance magus is seen as the immediate precursor of the seventeenth-century scientist, Giordano Bruno holds a significant place, and his tragic death early in the first year of the new century must still arrest our attention as symbolic of a great turning point in human history.


I. Original Works. Bruno’s Latin works are in Opera latine. Francisco Fiorentino, Vittorio Imbriani, C. M. Tallarigo, Felice Tocco, and Girolamo Vitelli, eds., 3 vols. (Naples-Florence, 1879–1891), also in a facsimile reprint (Stuttgart-Bad Cannstatt, 1962). Latin works discovered and published since this edition are Due dialoghi sconosciuti e due dialoghi noti, Giovanni Aquilecchia, ed. (Rome, 1957); and Praelectiones geometricae e ars deformationum, Giovanni Aquilecchia, ed. (Rome, 1964). The Italian works are collected in Dialoghi italiani, Giovanni Gentile, ed., revised by Giovanni Aquilecchia (Florence, 1957), which contains all the Italian dialogues in one volume; one of the works, La cena de le ceneri, has been published separately with intro. and notes by Giovanni Aquilecchia (Turin, 1955).

Translations of Bruno’s works include “Concerning the Cause, Principle, and One,” Dorothea W. Singer, trans., in Sidney Greenberg, The Infinite in Giordano Bruno (New York, 1950), pp. 77 ff.; “On the Infinite Universe and Worlds,” Dorothea W. Singer, trans., in her Giordano Bruno, His Life and Thought (New York, 1950), pp. 227ff.; Des fureurs héroïques, Paul-Henri Michel, trans. (Paris, 1954); The Expulsion of the Triumphant Beast, Arthur D. Imerti, trans. (New Brunswick, New Jersey, 1964); Giordano Bruno’s “The Heroic Frenzies,” Paul Eugene Memo, trans. (Chapel Hill, N.C., 1964).

II. Secondary Literature. A bibliography of Bruno’s works and of books and articles on him up to and including 1950 is Virgilio Salvestrini and Luigi Firpo, Bibliografia di Giordano Bruno (1582–1950) (Florence, 1958). Documentary sources on his life are Vincenzo Spampanato, ed., Documenti della vita di Giordano Bruno (Florence, 1933); and Angelo Mercati, ed., Il sommario del processo di Giordano Bruno (Vatican City, 1942). The standard biography is Vincenzo Spampanato, Vita di Giordano Bruno (Messina, 1921); on the trial, see Luigi Firpo, Il processo di Giordano Bruno (Naples, 1949).

The following brief selection from a vast literature includes books illustrative of the history of Bruno’s reputation: Domenico Berti, La vita di Giordano Bruno da Nola (Florence, 1867); Felice Tocco, Le opere latine di G. Bruno (Florence, 1889), and Le fonti più recenti del Bruno (Rome, 1892); J. Lewis McIntyre, Giordano Bruno (London, 1903); Giovanni Gentile, Giordano Bruno e il pensiero del Rinascimento (Florence, 1920); Leo Olschki, Giordano Bruno (Halle, 1924), also translated into Italian (Bari, 1927); Ernst Cassirer, Individuum und Kosmos in der Philosophie der Renaissance (Berlin-Leipzig, 1927), also translated into English by Mario Domandi (New York, 1963); Antonio Corsano, Il pensiero di Giordano Bruno (Florence, 1940); Eugenio Garin, La filosofia (Milan, 1947); Walter Pagel, “Giordano Bruno: The Philosophy of Circles and the Circular Movement of the Blood,” in Journal of the History of Medicine and Allied Sciences, 6 (1951), 116–125; Alexandre Koyré, From the Closed World to the Infinite Universe (Baltimore, 1957); Paolo Rossi, Clavis universalis (Milan, 1960), pp. 109–134; Paul-Henri Michel, La cosmologie de Giordano Bruno (Paris, 1962): Paul Oskar Kristeller, Eight Philosophers of the Italian Renaissance (Palo Alto, Calif., 1964), pp. 127–144.

This article is based on my books, Giordano Bruno and the Hermetic Tradition (Chicago, 1964), and The Art of Memory (Chicago, 1966). On Bruno, Gilbert, and Bacon, see my essay “The Hermetic Tradition in Renaissance Science,” in Art, Science, and History in the Renaissance, Charles S. Singleton, ed. (Baltimore, 1968), pp. 255–274.

Frances A. Yates

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Bruno, Giordano


(b. Nola, Italy, 1548; d. Rome, Italy, 17 February 1600), philosophy, physics, cosmology. For the original article on Bruno see DSB, vol. 2.

Bruno was slow to gain recognition for his scientific contributions for two reasons. First, he was condemned to the stake for his heretical theological views, and this led to efforts to expunge all traces of his works from public memory (damnatio memoriae). Hence, his works tended to be forgotten. Second, his conception of Nature was not mechanistic. He even took an interest in natural magic as a way to understand Nature. These aspects of his thinking have led historians of science, who tend to view the development of science as the development of mechanistic philosophy, to consider Bruno as more philosopher and magus than scientist. Yet between 1584 and 1588–1591, Bruno was the first to propose a scientific theory of the relativity of motion, spatial lengths, and time intervals.

An Infinite Universe. Bruno assented to the Copernican world system, but he went beyond it. He eliminated all the celestial spheres, to which celestial bodies were considered bound. He gave a physical basis to the new astronomical system: His alternative to Aristotelian physics was the medieval theory of impetus. To this theory he added a

dynamic atomism. Atoms, or monads, are not purely material and inert, but have power and form, as Democritus asserted. The vacuum is not empty but full of ether.

Since the thirteenth century the Church had condemned many points of Aristotelian physics, and a Christian natural philosophy of a sort had tentatively been constructed. Christian theology progressively deconstructed Aristotelian physics and cosmology by arguing from the standpoint of God’s absolute power (de potentia Dei absoluta). According to Bruno, the power of God’s love is actually infinite, and so the creation must be actually infinite, that is, made of living worlds and atoms, full of powers, without limit. Atomism and Christian theology thus led Bruno to conceive of the universe as infinite.

After the Reform had destroyed the univocal Catholic interpretation of the Bible, Bruno argued that the Bible gives people only ethical indications and no scientific truth about the universe. Bruno also had scientific reasons for holding that the universe is infinite. These include his atomistic physics and cosmology, and Tycho Brahe’s new astronomical observations of comets. Bruno himself argued that the stars only seem fixed because of their distance from people on Earth, and hence that the fixity of the stars cannot be used to show that the universe is finite. He also argued that mathematical abstractions can never correspond to physical measures and to physical reality. He thus countered mathematical arguments for a finite universe.

Relativity of Motion. According to Bruno, the motions of celestial bodies are not really circular, but rather are completely free in infinite ethereal space. Each body has a dynamic consistency, determined by that body’s own impetus, and is in motion in infinite space, as there are no bodies at rest. Moreover, there is no mathematical or physical center to the universe. Because no body is at rest, it is impossible to give an absolute measure of motion. Consequently, all motions are relative.

In The Ash Wednesday Supper (La cena de le ceneri, 1584, dialogue 3), Bruno sought to prove the Copernican system by arguing for the relativity of motion on a ship, an example already used in a simpler form by Jean Buridan, Nicole d’Oresme, Nicholas of Cusa, and Galileo Galilei. The relativity of motion considered by Bruno was based on the idea that everything belonging to a system participates in the motion of the system in such a way that any motion (uniform or nonuniform, rectilinear or curvilinear) without rotation does not modify any phenomenon. One cannot feel the Earth revolving around the Sun, because this motion does not affect phenomena. Rotations make a difference, but they are intrinsically relative motions among the different parts of the body. Bruno also argued that gravity is relative, giving a sort of principle of dynamic general relativity.

Galileo, in his Dialogue Concerning the Two Chief World Systems, Ptolemaic and Copernican (Dialogo sopra i due massimi sistemi del mondo, 1632), repeated some of Bruno’s arguments, but he never quoted him because Bruno was condemned by the Inquisition. Hence, people must attribute the principle of the relativity of motion to Bruno, not Galileo.

Relativity of Time and Space . The relativity of time follows from an infinite universe, as Bruno discussed in The Abruptly Ended Discourse in the College of France(Camoeracensis Acrotismus1588, XXXVIII) and The Immense Universe, the Numberless and Figureless Worlds(De innumerabilibus, immenso et infigurabili1591, VII.7). According to Aristotelian and medieval definitions, time is physically and cosmically given by the motion of the eighth sphere of fixed stars, because this motion is perfectly uniform, continuous, and simple, as required by a definition of time. If the universe is infinite, there are no spheres at all, and hence there is no privileged, perfectly uniform, continuous motion for the definition of time. The universe contains infinite motions, any one of which could be used for the definition of time. Since motion is used to measure time intervals, different motions define different, nonhomogeneous proper times. Motion affects time. Thus, the relativity of motion implies the relativity of time.

The relativity of space is already implicit in the notion that space is infinite and lacks a center, but for Bruno, spatial lengths and distances are also relative. He argued for this position in Camoeracensis Acrotismus(1588, XXVII, XXXII, XXXIV, XXXV, XXXVII), De innumerabilibus, immenso et infigurabili(1591, IV.6), and The Threefold Minimum and the Measure(De triplici minimo et mensura1591, II.5). Bruno started from a radical epistemological critique of measurability: motion affects, and places limits on, exact measurements. Measurements of space under different conditions of motion imply different spatial lengths. Hence, lengths are relative.

Galileo followed only Bruno’s idea that motion is relative, and only when motion is limited to uniform motion and relativity is considered as kinematic relativity, and not as dynamic relativity. Bruno’s general dynamic relativity was followed only by Gottfried Wilhelm Leibniz. In different perspectives, Bruno’s dynamic relativity was reconsidered, through Leibniz’s influence, by Henri Poincaré in his special relativistic dynamics and, through the influence of Poincaré, Benedict de Spinoza, and Ernst Mach, by Albert Einstein in his theory of general relativity.


Italy’s Instituto Nazionale di Studi sul Rinascimento has devoted a Web site to Giordano Bruno, available from that includes a bibliography of Bruno’s work. A complete archive of Bruno’s texts in Latin and in the vernacular, including indexes, is also available from this site, at

Giannetto, Enrico R. A. “La relatività del moto e del tempo in Giordano Bruno.” Physis 38 (2001): 305–336.

——. “Giordano Bruno and the Origins of Relativity.” In Albert Einstein, Chief Engineer of the Universe: One Hundred Authors for Einstein, edited by J. Renn. New York: Wiley, 2005.

Enrico R. A. Giannetto

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Bruno, Giordano (1548–1600)

BRUNO, GIORDANO (15481600)

BRUNO, GIORDANO (15481600), Italian philosopher. Born to a military father, in Nola near Naples, in 1548, Bruno was baptized Filippo. He became Giordano in 1565 on entering the Dominican monastery in Naples. He was ordained a priest in 1573, but was soon in trouble for reading forbidden books. Bruno was forced to flee from Naples, and later from Rome, to escape an official enquiry.

Discarding his monk's habit, Bruno traveled north through Genoa and Venice, giving private lessons on cosmology. In 1579, he left Italy for Geneva, where he found work with the printers. Bruno repudiated John Calvin's radical concept of predestination, and was soon obliged to leave Geneva after publishing a libel, no longer extant, criticizing one of the city's most distinguished professors of philosophy. He fared better in France where, after two years teaching philosophy at the University of Toulouse, he arrived in Paris in 1581.

Bruno was soon noticed by the French king, Henry III, for his art of memory which linked the classical art, considered as a part of rhetoric, with the use of memory icons as a part of logic proposed by the thirteenth-century mystic, Ramon Lull. Appointed as one of the royal lecturers, Bruno published in Paris in 1582 his first surviving work, De Umbris Idearum, which explains his art of memory. In the same year, Bruno published in Italian the comedy Candelaio, which paints a vividly realistic picture of the corrupt activities of plebeian Naples. It is thought by some to have influenced major Elizabethan dramatists such as Shakespeare and Ben Jonson.

In the spring of 1583, Bruno left Paris for London, where he became a gentleman attendant on the French ambassador, Michel de Castelnau, who was secretly supporting the cause of the Catholic Mary, queen of Scots. With the ambassador, he visited the court of Queen Elizabeth I and the University of Oxford, where he later returned to lecture on cosmology. His attempt to propose Copernicus's heliocentric astronomy was a disaster. Accused of plagiarism and treated with contempt, Bruno returned to London where, between 1584 and 1585, he wrote and published his six Italian dialogues, which argue for a post-Copernican, infinite universe in which each star is a sun, giving rise to an infinite number of solar systems similar to our own.

After returning to Paris in autumn 1585, Bruno wandered through central Europe teaching and publishing his philosophy in Wittenberg, Prague, Helmsted, and Frankfurt. In 1591, he published his Latin masterpiece, known as the Frankfurt Trilogy, prefixing his cosmological picture (De Immenso) with the first systematic modern treatise proposing an atomistic conception of matter (De Triplici Minimo). The second volume of the trilogy (De Monade) on Pythagorean number symbolism announces Bruno's final works, left unpublished at his death, which show an increased attention to magical and mystical themes in a Neoplatonic and Hermetic perspective.

Bruno returned to Italy in summer 1591, invited by a Venetian nobleman, Giovanni Mocenigo, to teach him his art of memory. In May 1592, Mocenigo denounced him to the Inquisition for heretical opinions. Bruno was arrested and tried in Venice until February 1593, when he was extradited to Rome. Refusing to recant, Bruno was burnt at the stake in Campo dei Fiori in Rome on 17 February 1600.

At the center of Bruno's philosophy lies his new picture of an infinite, homogeneous, atomistically articulated cosmos, full of infinite life. From this idea derives his concept of God as Monad, or the ineffable One whose seal or shadow is the infinite world; his refusal of the Christian incarnation on the basis that the whole universe, filled with the divine spirit, is an incarnation of God; his search for that God through a logical hunt that follows the traces of divine order observable within the natural universe; his idea of magic as filling the gap that opens up between the infinite whole and the finite mind of the philosopher, entrapped in time and space; his search for new mathematical and mnemonic arts capable of comprehending the infinite, universal whole.

Considered a precursor of major philosophers such as Baruch Spinoza or Friedrich Wilhelm Joseph von Schelling, Bruno was appreciated in the nineteenth century above all for his contribution to the scientific revolution and in the twentieth for his Hermetic magic and interest in the occult. The agenda for the new century appears oriented toward a more balanced and complete view of him as a thinker who amalgamated apparently conflicting doctrines of knowledge in a complex but rich oeuvre that Bruno himself referred to as "the Nolan philosophy."

See also Academies, Learned ; Cosmology ; Magic ; Philosophy ; Scientific Revolution ; Spinoza, Baruch.


Primary Sources

Bruno, Giordano. The Ash Wednesday Supper (1584), edited and translated by E. A. Gosselin and L. S. Lerner. Hamden, Conn., 1977. Reprint: Toronto, 1995.

. The Cabala of Pegasus (1585). Edited and translated by S. L. Sondergard and M. U. Sowell. New Haven and London, 2002.

. Cause, Principle and Unity (1584) and Essays on Magic. Edited and translated by R. J. Blackwell and Robert de Lucca. Introduction by Alfonso Ingegno. Cambridge, U.K., 1998.

. The Expulsion of the Triumphant Beast (1584). Edited and translated by A. D. Imerti. New Brunswick, N.J., 1964.

. The Heroic Frenzies (1585). Edited and translated by P. E. Memmo. Chapel Hill, N.C., 1964.

. His Life and Thought, with Annotated Translation of his Work, On the Infinite Universe and Worlds (1584). Edited and translated by D.W. Singer. New York, 1950.

. On the Composition of Images, Signs and Ideas (1591). Edited and translated by C. Doria and D. Higgins. New York, 1991.

. Opera latine conscripta. Edited by F. Fiorentino et al. 3 vols. in 8 parts. Naples and Florence, 18791891. Facsimile reprint, 1962.

Secondary Sources

Aquilecchia, Giovanni. Schede bruniane (19501991). Manziana, 1993.

Canone, Eugenio. Giordano Bruno 15841600: Mostra storico documentaria. Florence, 2000.

Ciliberto, Michele. Giordano Bruno. Rome and Bari, 1990.

De Léon Jones, Karen. Giordano Bruno and the Kaballah. New Haven and London, 1997.

Firpo, Luigi, and Quaglioni, Diego. Il processo di Giordano Bruno. Rome, 1993.

Gatti, Hilary. Giordano Bruno and Renaissance Science. Ithaca, N.Y., 1999.

. The Renaissance Drama of Knowledge: Giordano Bruno in England. London, 1989.

Gatti, Hilary, ed. Giordano Bruno: Philosopher of the Renaissance. London, 2003.

Hodgart, Amelia Buono. Giordano Bruno's 'The Candle Bearer': An Enigmatic Renaissance Play. Lewiston, U.K., 1997.

Mendoza, Ramon. The Acentric Labyrinth: Giordano Bruno's Prelude to Contemporary Cosmology. Shaftesbury, U.K., 1995.

Ordine, Nuccio. Giordano Bruno and the Philosophy of the Ass. New Haven and London, 1996.

Yates, Frances. Giordano Bruno and the Hermetic Tradition. London, 1964.

Hilary Gatti

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Giordano Bruno

Giordano Bruno

The Italian philosopher and poet Giordano Bruno (1548-1600) attempted to deal with the implications of the Copernican universe. Although he made no scientific discoveries, his ideas had much influence on later scientists and philosophers.

Giordano Bruno was born at Nola in southern Italy. His baptismal name was Filippo, but he took the name Giordano when he entered a Dominican monastery in Naples in 1565. During his stay in different monastic houses in southern Italy, he acquired a vast knowledge of philosophy, theology, and science. Because he developed unorthodox views on some Catholic teachings, Bruno was suspected of heresy and finally fled the monastic life in 1576. This experience reveals much about Bruno's personality. His love for knowledge and hatred of ignorance led him to become a rebel, unwilling to accept traditional authority. The price he paid for this independence was persecution and condemnation in many countries.

After making his way through northern Italy, Bruno sought refuge at Geneva in 1579. His criticism of a Genevan professor, however, forced his withdrawal from that city. The next 2 years were spent in Toulouse, where he was granted a master's degree and lectured on Aristotle. In 1581-1582 he stayed in Paris and published his first significant set of writings, in which he explained a new method for memory training and commented on the logical system of Raymond Lully.

In 1583 Bruno traveled to England, where he lived for 2 years. While there, he became friendly with some prominent Englishmen, publicly praised Queen Elizabeth I, and held a disputation at Oxford on the Copernican and Aristotelian conceptions of the universe. Most important, he published some of his best works in England during 1584-1585, namely, La Cena de le Ceneri (The Ash Wednesday Supper); De l'infinito universo et mondi (On the Infinite Universe and Worlds); and De la causa, principio et uno (Concerning the Cause, Principle, and One). In these works Bruno attempted to come to grips with the meaning of the new conception of the universe that Copernicus had developed. Bruno conceived of the universe as infinite, composed of a plurality of worlds. For him the universe has a unity that signifies a prevailing order-individual things are not isolated but are animated by a common life and a common cause. This cause is immanent, not transcendent, and the soul which gives life to the whole is God. It is God who "is not above, and not outside, but within and through, all things." It is not surprising that later examiners of Bruno's system described it as pantheistic. Bruno also published an Italian dialogue, De gli eroici furori (1585; The Heroic Furies), in which he presents the Renaissance conception of Platonic love.

Returning to France in 1585, Bruno was forced to leave that country in 1586 because of his attacks on Aristotelian philosophy. He then went to Germany, where he achieved some acclaim as a result of his lectures at the University of Wittenberg and published some works centered primarily on logic. After further travels he settled briefly in Frankfurt am Main, where he wrote a series of poems in Latin. In the three most important ones (all 1591), De minimo (On the Minimum), De monade (On the Monad), and De immenso (On the Immense), he examined what is infinitely small and infinitely great in the universe.

In 1592 Bruno went to Venice on the invitation of a Venetian nobleman who later betrayed him to the Catholic Inquisition. Bruno was arrested and imprisoned in Rome, where after a lengthy confinement and a trial for heresy he was burned at the stake on Feb. 17, 1600.

Further Reading

There is an extensive literature on Bruno in many languages. The best English biography is Dorothea Waley Singer, Giordano Bruno: His Life and Thought (1950). This work also includes a translation of Bruno's important work On the Infinite Universe and Worlds. Older biographies are J. Lewis Mclntyre, Giordano Bruno (1903), and William Boulting, Giordano Bruno: His Life, Thought, and Martyrdom (1916). The former is divided into two sections, one on his life, the other on his philosophy. Among the specialized works on Bruno are Sidney Greenberg, The Infinite in Giordano Bruno, with a Translation of His Dialogue: Concerning the Cause, Principle, and One (1950); Irving Louis Horowitz, The Renaissance Philosophy of Giordano Bruno (1952); John Nelson, Renaissance Theory of Love: The Context of Giordano Bruno's Eroici furori (1958); and Frances A. Yates, Giordano Bruno and the Hermetic Tradition (1964).

Additional Sources

Yates, Frances Amelia, Lull & Bruno, London; Boston: Routledge& K. Paul, 1982.

Bossy, John, Giordano Bruno and the embassy affair, New Haven: Yale University Press, 1991. □

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Bruno, Giordano (1548–1600)

Bruno, Giordano (15481600)

Italian philosopher who was executed for his teachings and beliefs that were contrary to Catholic doctrine. Born in Nola, in the Kingdom of Naples, Bruno was the son of a soldier. He was a prodigy as a scholar and joined the Dominican Order, becoming a priest in 1572. He studied a wide range of philosophies and also took a keen interest in astronomy and mathematics, training himself to prodigious feats of memory that led many to suspect him of dabbling in the occult arts. He took up the Hermetic tradition, based on the writings of the ancient seer Hermes Trismegistus, a renowned figure since the Middle Ages and a representative of ancient Egyptian wisdom and magic. Bruno also studied the works of Saint Thomas Aquinas, a leading medieval scholar; Marcilio Ficino, a Renaissance Neoplatonist, or follower of Aristotelianism; and German philosopher Nicholas of Cusa. Bruno grew familiar with the heliocentric universe proposed by Nicolaus Copernicus, but took it a dangerous step further by teaching that the universe was infinite, and that the earth was only one among an infinite variety of worlds with no particular importance. This ran counter to Christian doctrine.

Accused of heresy by the order of friars called Dominicans, Bruno left Naples in 1576 for Rome, then traveled to Geneva, where he joined the Protestant Calvinist sect but was excommunicated for slandering the philosopher Antoine de la Faye. In 1579 he left Geneva, unhappy with the strict Calvinist methods, and became a professor of philosophy at Toulouse, France. Under constant scrutiny wherever he went, he spent time in Paris and then London, where he worked in the service of French ambassador Michel de Castelnau. In England his published works and his promotion of the Copernican system offended some. He also came under suspicion for a powerful mnemonic system of memory that he described in his works The Shadow of Ideas, The Art of Memory, and Circe's Song. In 1584 he completed two of his most important works, On the Infinite Universe and Worlds and The Expulsion of the Triumphant Beast. Bruno arrived in Prague in 1588. He was excommunicated there by Lutheran Church officials and had to flee the city. He returned to Germany in 1591. At the invitation of a Venetian noble, Giovanni Mocenigo, he moved back to Italy and became a memory tutor to Mocenigo. The two were soon at odds over Bruno's unyielding philosophy and abrasive personality. Mocenigo denounced Bruno, who was arrested in May 1592 and charged with heresy and blasphemy. He was transferred to Rome and imprisoned, finally tried for his negative views on Catholic dogma, including the rites of the Mass and the nature of the Trinity, for practicing magic, and for his heretical belief in a multiplicity of worlds. He was found guilty after a trial that lasted seven years and burned at the stake in 1600.

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Bruno, Giordano

Giordano Bruno (jōrdä´nō brōō´nō), 1548–1600, Italian philosopher, b. Nola. The son of a professional soldier, he entered the Dominican order early in his youth and was ordained a priest in 1572, but he was accused of heresy and fled (c.1576) to take up a career of study and travel. He taught briefly at several cities including Toulouse, Paris, Oxford, and Wittenberg, but, personally restless and in constant opposition to the traditional schools, he found no permanent post. He was particularly known for his prodigious memory, and at times taught mnemonic technique. His major metaphysical works, De la causa, principio, et uno (1584, tr. The Infinite in Giordano Bruno, 1950) and De l'infinito, universo et mondi (1584), were published in France. Further works appeared in England and Germany. Bruno also wrote satire and poetry. In 1591 he returned to Venice, where he was tried for heresy by the Inquisition. After further trial and imprisonment at Rome, he was burned to death.

Bruno challenged all dogmatism, including that of the church-sanctioned Aristotelian physics and earth-centered cosmology as well as the controversial Copernican cosmology, the main tenets of which, however, he upheld. He believed that our perception of the world is relative to the position in space and time from which we view it and that there are as many possible modes of viewing the world as there are possible positions. Therefore we cannot postulate absolute truth or any limit to the progress of knowledge. The first to enunciate what is now called the cosmic theory, he pictured the world as composed of individual elements of being, governed by fixed laws of relationship. These elements, called monads, were in constant motion, ultimate, and irreducible and were based on a pantheistic infinite principle, or cause, or Deity, manifest in us and in all the world. Bruno's influence on later philosophy, especially that of Spinoza and Leibniz, was profound, and he is widely considered a forerunner of modern science.

See biography by I. D. Rowland (2008); P. H. Michel, The Cosmology of Giordano Bruno (tr. 1973); S. Drake, Copernicus—Philosophy and Science: Bruno—Kepler—Galileo (1973); F. A. Yates, Lull and Bruno (1982).

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