Miss Frances Yates’s book is an important addition to our knowledge of Giordano Bruno. But it is even more important, I think, as a step toward understanding the unity of the sixteenth century, when the late Renaissance turned into the scientific revolution. The new scientists of that time were deeply influenced by humanist concepts, and this influence has notoriously been neglected. For example, the writers and painters of the Renaissance were excited by a mystic religion of nature which they found in some books from the east; but only recently has it been seen that the same mystic ideas also fired philosophers and astronomers. Miss Yates sets out these ideas, and their history, with exemplary clarity; and since I find this the richest part of her book, I will begin there.

Sometime about 1460, when Cosimo de’ Medici was collecting his great library in Florence, there was brought to him by one of his buyers from Macedonia an incomplete copy of the Corpus Hermeticum: a book which was reputed in the Middle Ages to contain prophetic secrets and magic from ancient Egypt. Cosimo could not read the Greek text, and he gave it to Marsilio Ficino to translate into Latin with the other Greek works which were coming from Byzantium. Ficino was just starting on the most important of these finds, the dialogues of Plato, when Cosimo in 1463 peremptorily ordered him to put them aside in order to translate the Corpus Hermeticum first. Cosimo was in his seventies and we must guess that, among the books that he wanted to read before he died in 1464, he ranked the Corpus Hermeticum above Plato.

The Hermetic books are a series of revelations about the nature and destinies of gods and men, and they are supposed to have been disclosed by the Egyptian gods to a priest who came to be called Hermes Trismegistus, Hermes the Three Times Great, after the god of wisdom. The Hermetic books in general, and the Corpus Hermeticum in particular, take their name from this Egyptian priest. He was accepted as a real man who lived before the Greek philosophers and about the time of Moses; Ficino speculated whether he might not have been Moses himself. The snatches of Greek and Biblical thought and stories with which the Hermetic books are peppered were read as marvelous anticipations. In fact, of course, they were copies, and the Hermetic books are fakes. But that was not proved until one hundred and fifty years after Ficino’s translation, and fourteen years after Bruno died.

Miss Yates’s lucid analysis of the Hermetic books helps particularly to clarify the change in attitude to them between the Middle Ages and the Renaissance. In the Middle Ages, the Hermetic books had been treated as recipes for magic, and read in secret. This was because Saint Augustine had condemned the writings of “Hermes the Egyptian, called Trismegistus” and called them impious. Augustine singled out for attack two passages from a Hermetic book, the Asclepius, of which a Latin text existed. In one of these passages, Hermes describes how the Egyptians brought the statues of their gods to life by drawing spirits into them. In the other, Hermes foretells that the religion of his time will come to an end, and will be ousted by a religion which despises the natural world. Augustine interprets this as a true prophecy of the coming of Christ, but he condemns Hermes for having got it from evil spirits. Since this passage was written, like other Hermetic books, after the first century, it was in fact not a prophecy but a lament: the writer thinks back with longing to the days when nature was revered as rich and beautiful and men were not obsessed by the austerities of Christ and Rome.

When Ficino published his rapid translation of the Corpus Hermeticum (it was copied widely in manuscript before it was printed in 1471), he had therefore to walk warily between his own enthusiasm and the suspicion of the Church. He could not ignore the thunder of Saint Augustine, but he made much of another Father of the Church who had accepted Hermes as a respectable prophet. Ficino presents the Corpus Hermeticum as the pure first spring of all religion, from which the divine wisdom flowed to the Persians, the Jews, the Greeks, the Christians, and at last to the Renaissance.

Ficino’s translation of the Corpus Hermeticum, and his own later writings that stem from it, had a deep influence on the Renaissance. They were not, like the Greek classics, openly pagan; there was about them still a decent air of Christian self-effacement; and yet they plainly overtopped the dogma of the Church and reached and stretched into the natural world with the pleasure of a man getting out of bed. Here all religions were (almost) one, and all emotions were one: the ecstasies of the spirit were not cut off from the feeling that physical nature also is mysterious and beautiful. The sky suddenly was filled not with moral lessons (what could be more colorless than the Old Testament story of the rainbow) but with the visible fire of a natural power that loved to express itself splendidly. The heavenly bodies became, as it were, the personal friends of artists and philosophers alike, who felt in their movements a sense of communion between human mathematics and the universal order.


All this is present in the scientific work of the Renaissance as much as in the literary work. It was until recently overlooked in the scientific work, simply because humanist scholars did not read that work in Jacob Burckhardt’s day. But no one who now reads closely Copernicus’s book on the revolution of the planets, which he began about 1507 can miss the signs that he was a humanist gentleman who felt all the enthusiasms of his culture. Indeed, as Miss Yates points out, Copernicus refers to Hermes Trismegistus by name in a passage which recalls that Hermes had written:

The sun illuminates the other stars not so much by the power of its light, as by its divinity and holiness, and you should hold him, O Asclepius, to be the second god, governing all things.

Yet the direct reference is less telling than the tone of everything that Copernicus says about the sun, which is shot through with the conviction that the sun alone has the right to be at the center of the universe—the center of man’s universe. To Copernicus as much as to the Renaissance painters, the sun personifies the divine energy as man does.

This vision of the sun at the heart of creation, a deification and humanization together, runs from Ficino and others all through the Renaissance. It is wider than the Hermetic tradition, and draws also on doctrines from Plato and from Pythagoras. And it was certainly shared by those philosophers, such as Giordano Bruno, who accepted the Copernican system, and understood by those who did not. Miss Yates prints an important eyewitness account (discovered by Robert McNulty in 1960) which shows that when Bruno lectured on the Copernican system in Oxford in 1583, his hearers were unconvinced but were quick to spot the quotations from Ficino.

There was a second and darker strand in the Hermetic tradition which ran on into the Renaissance. The Hermetic books inspired an open admiration for the magnificent force of nature; but they also continued to inspire, as they had done in the Middle Ages, a closed belief in a magic which could command this force. Ficino was drawn to such magic but was too timid to meddle much; he only sang Orphic songs to the lyre. His younger friend Pico della Mirandola was less cautious. In 1486 he offered to debate in Rome nine hundred theses (to be prefaced by his great oration on the Dignity of Man) of which twenty-six concerned magic and another seventy-two drew on the Cabala. Among these is the thesis that magic and Cabala are the strongest proof of the divinity of Christ:

Nulla est scientia, que nos magis certificet de diuinitate Christi, quam Magia & Cabala.

This outrageous claim, and several others, were condemned by a Papal bull as heretical, and Pico fled to France. Yet he was absolved by a new Pope in 1493, and (having become a patron of Savonarola) was lavishly commended for his Christian inspiration.

These struggles and uncertainties about magic are part of the larger fight against the Renaissance worship of nature which went on within the Church, to and fro, for another hundred and fifty years; the Renaissance was not finally defeated until the trial of Galileo in 1633. Meanwhile, the humanist spirit continued to express itself in some extravagant ways, and the natural magic—the inherent sympathy between man and things—which was supposed to be communicated by the Hermetic books was one of them. Miss Yates’s careful book leaves no doubt that Giordano Bruno, who has hitherto been presented as a pioneer and martyr of Renaissance enlightenment, was a student of Hermetic magic.

Yet, when it has been proved that Bruno was involved (and deeply involved) in magic, he is not turned either into a knave or a fool. The Renaissance magus was not a conjurer or a table-rapper. In a phrase which Pico takes from Plotinus, he was “the servant of nature and not a contriver.” His magic was not meant to change the march of physical or biological processes; Bruno did not want to make walls rise up or people fall ill—or even fall under his spell. Like the other restless and intransigent giants of his age, he was impatient not for power but for understanding; for all of them, power counted only as the proof of understanding. They wanted to enter into the hidden structure of nature, and to grasp in intellectual ecstasy the unity between the mind and the world. If Bruno’s search in magic was more active than that of earlier humanists, if he made talismans and mnemonics, it was because he had the practical bent of a scientist. A hundred years after Bruno died, and two hundred years after Ficino and Pico, Isaac Newton still filled notebook after notebook with speculations in alchemy and numerology.


It is therefore odd that Miss Yates, who does not despise the Renaissance magi, presents the discovery that Bruno was one of them as a slight to him. Somehow her own discovery has sapped her sympathy. In the end, she treats Bruno’s advocacy of the system of Copernicus, and the bold philosophy that he based on it, as less important than his conventional interest in magic.

For example, Miss Yates holds that the newly found account of Bruno’s lectures in Oxford proves that he leaned more on Ficino than on Copernicus. And it is true that the cleric who wrote this hostile account makes much of the taunt that Bruno was cribbing from Ficino. Yet before this taunt, he makes another: that Bruno was

telling vs much of chentrum & chirculus & circumferenchia (after the pronunciation of his Country language).

However Bruno pronounced these words, they do not come from the Corpus Hermeticum. They can only have been used by someone who was genuinely trying to explain the mathematics of Copernicus.

Again, Miss Yates says (as she has done before) that Bruno misunderstood Copernicus. Copernicus held that the earth goes around the sun and the moon around the earth, but Bruno thought that the earth and the moon go around the sun together. This is certainly so; but it does not follow that Bruno was quite wrong. The earth and the moon do form a common system, and what goes around the sun is their common center of gravity. Bruno could not have known the mechanics of this system, and therefore he could not know that it is dominated by the large mass of the earth. Yet he may have had, rightly, an intuitive sense that the earth and the moon hang together, and he may have tried to express this in his interpretation of the Copernican diagram. Miss Yates is surely going too far when she dismisses Bruno’s version of the diagram as “a hieroglyph, a Hermetic seal,” and lumps it with the fanciful symbols of the Rosicrucians.

Giordano Bruno was one of the powerful speculative minds in the transition from the late Renaissance to the scientific revolution, and Miss Yates’s book about him is enlightening because it shows how interwoven were all the strands in that transition—even the unexpected strand of magic. Bruno was born in 1548, five years after Copernicus published his book. He accepted the dangerous thought of Copernicus, and he pushed it to the more dangerous conclusion that the universe is infinite and contains an infinity of worlds. He propounded these unpopular ideas in the universities of Italy, of France, of England and of Germany, wandering through Europe with nothing to support him except his own headstrong personality. Miss Yates has shown that he was in every way a man of his age, and that the Hermetic tradition was alive in him as in the whole age. Bruno’s god was nature, in philosophy, in magic, and in religion. The Inquisition feared him as it feared all the new men of that age of transition, and it got him back to Rome and burned him alive on the Campo de’ Fiori on February 17, 1600.

This Issue

September 10, 1964