Galileo Galilei
Galileo Galilei; drawing by David Levine

This book consists of essays, articles, and lectures written by Giorgio de Santillana during the last twelve years, nearly all of them already published in various journals and collective works. I am heartily in favor of this practice. So much valuable work is otherwise effectively buried in periodicals, Fest-schriften, etc. Moreover, such collections can give a more complete picture of the range of a scholar’s interests and the consistency of his thought than do his separate books, as is the case, for example, with recent collections of Ernst Gombrich and Karl Popper. Santillana’s range is staggeringly wide; as Hugh Trevor-Roper says in his Foreword:

He will quote Hrabanus Maurus and Bertold Brecht as effortlessly as Metrodorus or Athanasius Kircher, and carry us with him, a little breathless perhaps, and dizzy with his throw-away allusions and polyglot versatility, from Anaximander and Parmenides to Einstein and Oppenheimer, from Hesiod and the Epic of Gilgamesh to Kafka, Auden, Salvemini and Simone Weil.

Since I am ignorant about some of these subjects, this review may well be unfair by reason of its omissions and its concentration on the few topics I happen to know a little about.

Trevor-Roper also rightly praises Santillana’s broad and imaginative approach to the history of science, and remarks that it is these qualities that make his best-known book, The Crime of Galileo, so dramatic and thought-provoking. There are indeed many examples in these essays of the illuminating insights which result from such an approach; but these go together with some very worrying defects.

In the piece on Newton, for example, Santillana is surely right in stressing the importance of Newton’s belief in an ancient tradition of wisdom, in a prisca theologia that included scientific truths, as recent work by J.E. McGuire and P.M. Rattansi on the unpublished Scholia to Book III of the Principia has amply shown. But what are we to make of the following:

The subject of the Hermetic Philosophy (so named after the mythical master, Hermes the Thrice-Greatest) was the cosmos itself and its interlocking forces; not the cosmos of our cosmonauts, to be sure, nor even that of Copernicus and Galileo. It was the archaic Universe, which went back to the grey dawn of our civilization, brought forth by powerful minds lost in anonymity, the object of many great thinkers in successive ages—now lost to modern consciousness but deeply studied by Newton in a multitude of texts that no one can even read now, or cares to.

Now it is true, and significant, that Newton did read the Corpus Hermeticum, though Santillana gives no evidence for it. It may be true that the Hermetic cosmology goes back “to the grey dawn of our civilization”; the texts, however, are of the second and third centuries A.D., and their content is typical of the Gnosticism of that age, as the first of Festugière’s four volumes on La Révélation d’Hermès Trismégiste shows in detail. But it is certainly not true that no one can now read the Corpus Hermeticum, since Nock’s and Festugière’s excellent edition and translation of it was completed in 1954, or that no one cares to: witness Frances Yates’s Giordano Bruno and the Hermetic Tradition.

Another example is the lecture on Bruno and Leibniz, where firmly, and I think rightly. Santillana places the latter in the same Platonic or Pythagorean tradition as the former. He is not positing any direct connection between the two; but, since Leibniz did correspond with Toland on the subject of Bruno, and was sent by Toland extracts from the Spaccio della Bestia Trionfante, it seems a pity not even to mention this fact. A more serious criticism can be made of the starting point of this lecture. Santillana begins by quoting, without naming the author, from the Timaeus the passage (50 A-C) in which Plato uses the analogy of a lump of gold which is made constantly to take different forms, and then comments:

Ce passage, ainsi tiré de son contexte, a l’air d’une paraphrase cartésienne où le morceau de cire serait remplacé par du métal…. Il n’en est rien, vous l’avez déjà reconnu, il vient du Timée, et il s’agit de Dieu. On est tenté de penser que le Dieu de Platon et la matière de Descartes se ressemblent singulièrement par un côté du moins.

What on earth has happened here? The passage is in fact about the “receptacle,” i.e., Plato’s equivalent of our space, which receives the constantly changing shapes of the physical universe. If Santillana is putting forward the highly original, but I think untenable, theory that the receptacle is Plato’s God, then the reader should at least be given some argument in support of it. But it seems to me more likely that he was relying on a faulty memory both of the Timaeus and of Plato’s creating god, the Demiurge. That this is the explanation is borne out by the general lack of references in this book. The usual practice of giving precise references has two very important virtues: first, it enables other scholars to use one’s work and build further on it, and secondly, it forces one to look passages up again and thus avoid bad misinterpretations of them. An equally extraordinary example of misinterpretation occurs in the article “The Seventeenth Century Legacy” (and also in “Galileo Today”). Having mentioned Kepler’s rejection of an infinite universe, Santillana goes on:


The need for a finite universe, well and warmly contained within its outer glacial limits, is stronger in him than his own adventurous imagination. Fifty years later, Pascal puts it with his usual frankness: “It will be a good idea,” he writes in fragment 218, “not to go any deeper into the opinion of Copernicus.”

Here, thanks to the unusual presence of a reference, we can quickly look up the original, and find:

Cachot. Je trouve bon qu’on n’approfondisse pas l’opinion de Copernic: mais ceci!…Il importe à toute la vie de savoir si l’âme est mortelle ou immortelle.

The “cachot” is a reference to Fr. 200, which describes a man in a dungeon who has an hour in which he could save himself from death, and who spends the time playing piquet. The sense of Fr. 218 is then: it is reasonable not to bother to decide between rival astronomical theories, but crazy not to find out whether there is an afterlife or not, and thus risk falling for all eternity “dans les mains d’un Dieu irrité.” That is to say, the fragment tells us nothing about Pascal’s attitude to the Copernican theory, let alone the infinity of the universe. Here, the mistake is less easily explicable by the supposition of a quotation from memory, since the infinity of the universe plays a major part in Pascal’s apologia—“le silence éternel de ces espaces infinis m’effraie.”

Among the several interesting topics in this book that I am not competent to discuss are very ancient astronomy and cosmology—what lies behind the pre-Socratics. Santillana has evidently done a lot of work on this subject, and it may well be that, if I knew more about it and could understand it better, I would find this inevitably conjectural history more convincing. But it is disquieting that in some places where he deals with matters which I ought to understand he seems to me to be writing nonsense. In “Prologue to Parmenides,” for example, he has occasion to mention the Golden Section and the fact that this proportion involves an irrational number; he then goes on:

We might compare to this “problem” the immense efforts of harmonic theory to divide the octave, with its 12 half-steps, into equal parts (stumbling-block: the fifth) not only in Antiquity, but in the very same manner in China. The golden section gives for the relevant numbers:

5:3,1 8:4,9 12:7,4 13:8,0

I cannot make any sense of this. He seems to be talking about equal temperament; in which case the “stumbling-block” is not the fifth but the semitone. I do not see what connection there is between the Golden Section and the ratios of equal temperament, except that both involve irrationals, but irrationals of a different kind. The ratio of an equally tempered semitone is 12√2; the formula for the Golden Section, if a = the whole and b = the larger part, is a/b = b/(a-b) or b =a(√5-1)/2. The ratios Santillana gives can be read as approximations to the Golden Section (e.g., if a=13 and b = 8, then b2=64, a(a-b)=65); but to what musical ratios are they “relevant”?

As one would expect, Galilei and his conflicts with the Church have a prominent place in these essays, and Santillana has some interesting points to add to his book. He notes that, since his publication in 1955 of the evidence and arguments that the famous injunction of 1616 was a forgery, “not one authorized voice was raised to contradict me,” and suggests that this would have been a good occasion for the Church to annul the sentence and rehabilitate Galilei, especially since “I had made a good case for pinning down the guilt on a small group of minor officials who had plotted and acted on their own.” He goes on:

Pope Urban stood now in the light of history as a chief badly deceived by his subordinates. He was entitled to rehabilitation himself.

And, in another essay, Urban VIII is described as a man who, apart from the trial, “showed himself intelligent, open-minded, and far from ungenerous.” Here I would like to recall some facts which have been known for some time, most of them summarized in my book on magic; but they have not, I think, been brought into connection with the trial of Galilei. They may modify this view of Urban, and might perhaps throw a new light on his motives in insisting on the condemnation of Galilei and his book.


Urban VIII was a firm believer in astrology, and his diplomatic adversaries in Rome, the Spanish, took advantage of this belief by encouraging predictions of his death and making noisy preparations for the next conclave. The predictions were first for the year 1628, in which a solar eclipse occurred in December, and then for 1630, with a solar eclipse in June. It is almost certain that in both these years the Pope performed with Tommaso Campanella, an heretical Dominican, magical rites designed to protect the Pope from the dangerous influences of the eclipse, to which his horoscope made him particularly liable. These rites had been adapted by Campanella from Ficino’s magic, and appeared in print in 1629, without his consent, in the seventh book of his treatise on astrology.

The magic was of course successful. In 1631 the Pope issued a Bull against astrology, composed probably with Campanella’s help, which, while confirming in general terms the condemnations of Sixtus V’s Bull of 1586, specifically condemned only predictions of the death of princes, and especially Popes. In May 1630 rumors were spread that Galilei, then in Rome, and Campanella were predicting that the death of Urban would take place that year (see Galilei, Opere, ed. naz., XIV, 103). The rumors were surely unfounded as far as Galilei is concerned; but it should be remembered that he did cast horoscopes. In July 1630 Orazio Morandi, Abbot of Santa Prassede and a friend of Galilei’s, was arrested for having made astrological predictions of the Pope’s death in 1630 and having circulated them; he died in prison before being tried.

In August 1630 Castelli wrote to Galilei, who had returned to Florence, that, for reasons he dared not write down, it would be better for Galilei to have his Dialogo printed at Florence and as quickly as possible. The work was printed by February 1632, but, owing to the plague, was not on sale in Rome until June. By August the sale had been suspended and Urban was setting up a special commission to examine the book. On August 21 Campanella, who had published an apologia for Galilei in 1622, wrote to him to suggest that the Grand Duke of Tuscany should press for Campanella to be a member of this commission. The suggestion was acted on, but without success. But by October Campanella was badly frightened and wrote to Galilei to apologize for withdrawing his support. In June 1633 Galilei, under threat of torture, recanted and was sentenced. That Urban’s belief in and fear of astrology and magic continued up to this time is shown by the fact that in 1635 Giacinto Centini, a nephew of Cardinal di Ascoli, was beheaded and two monks were hanged for having made astrological predictions of the Pope’s death and done their best, by means of black magic, to make them come true.

Now Campanella’s thought and action throughout his life was dominated by his belief that the millennium was imminent and was heralded by the gradual approach of the sun to the earth, which it would finally consume—the sun, the center of love, would absorb the earth, the center of hate. But before this final consummation Campanella’s highly unorthodox Utopia, his Città del sole, would be established on earth. In 1599, he had been imprisoned at Naples, after the failure of his Calabrian revolt, which was to have realized his city of the sun, and he remained there for twenty-seven years, writing copiously. By 1616, when he wrote his Apologia for Galilei, he seems to have accepted the Copernican theory, but this did not change his astrology or eschatology—indeed a heliocentric system fitted in well with his strong tendency toward sun-worship. In 1626 he was released by the Spaniards and found himself in prison at Rome. Campanella’s millennarist hopes were now centered on the Pope. If he could gain Urban’s favor, then missionaries, trained by Campanella, would go forth from Rome to convert the whole world to a reformed, “natural” Catholicism, which would introduce the millennium, the universal city of the sun. By means of his anti-eclipse magic he nearly succeeded. By April 1629 he was released from prison, and by the next year he had obtained the Pope’s permission to found at Rome “un Collegio Barberino de Propaganda Fide,” for the training of missionaries according to his own principles. But from the end of 1631 Campanella’s position at Rome and his influence over Urban steadily declined. He transferred his eschatological expectations to the French monarchy, and in 1634 left Rome secretly for France, where he eventually celebrated the birth of the future Louis XIV in an imitation of Virgil’s 4th Eclogue as the coming ruler of the city of the sun, le roi soleil. He died in 1639, having once more tried his anti-eclipse magic, this time unsuccessfully.

It was long ago suggested (see F.H. Reusch, Der Process Galilei’s und die Jesuiten, 1879, p. 200) that Castelli’s advice to have the Dialogo printed at Florence may have had something to do with Urban’s proceedings against astrologers in 1630-1. But the relevance of the rest of this strange story to the Galilei trial has not, so far as I know, even been discussed. I cannot yet see how the jig-saw pieces fit together; but I feel that they all belong to the same puzzle. At the very least, this story gives a background of panic-stricken superstition, sun and star worship, and millennarist expectations of universal Christian monarchy, against which the trial should be seen. Although Urban’s fury against the Dialogo can be largely accounted for by Galilei’s having put the Pope’s pet argument into the mouth of the Aristotelian Simplicio and by the machinations of Galilei’s Jesuit adversaries, I think there may also have been other causes. As Santillana has suggested, Urban’s frustration at the disastrous results of his pro-French policy must have produced in him a state of acute anxiety and irritation. Here may be one clue to the puzzle. If, in 1630-1, Urban believed not only in Campanella’s astrological magic but also in his sun-centered millennarist hopes of a universal, reformed Catholic monarchy, which Urban’s pro-French policy was to help bring about, then, by the autumn of 1632, with Gustavus Adolphus, in alliance with Richelieu, conquering Catholic Germany, Campanella may well have seemed to the Pope a false prophet, and perhaps in league with Galilei, whom Campanella was in fact trying to support—both of them implicated in the terrors of the eclipse of 1630, both of them thinly disguised heliocentrists, both of them attributing a new, perilous importance to the sun.

There is evidence that at this time the Holy Office was contemplating proceedings against Campanella as well as Galilei; was it perhaps prevented by Urban’s not wishing to risk that Campanella, cunning, but also courageous, might mention those anti-eclipse rites of 1630—the sealed room, the seven torches, the incense, the prayers and the music, and the astrologically distilled liqueurs?

This Issue

January 30, 1969