gms | German Medical Science

59th Annual Meeting of the German Society of Neurosurgery (DGNC)
3rd Joint Meeting with the Italian Neurosurgical Society (SINch)

German Society of Neurosurgery (DGNC)

1 - 4 June 2008, Würzburg

Girolamo Cardano and the “German Friends”: Johannes Petreius, Georg Joachin Rheticus, Andreas Osiander, Philipp Melanchthon. A rather neglected European history of the influence and connection between the culture of Italy and Germany in the 16th century

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Deutsche Gesellschaft für Neurochirurgie. Società Italiana di Neurochirurgia. 59. Jahrestagung der Deutschen Gesellschaft für Neurochirurgie e.V. (DGNC), 3. Joint Meeting mit der Italienischen Gesellschaft für Neurochirurgie (SINch). Würzburg, 01.-04.06.2008. Düsseldorf: German Medical Science GMS Publishing House; 2008. DocP 051

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Published: May 30, 2008

© 2008 Bortoluzzi.
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Girolamo or Hieronimo Cardano's name was Hieronymus Cardanus in Latin and he is sometimes known by the English version of his name Jerome Cardan. Cardano was born the 24 Sept 1501 in Pavia, Duchy of Milan and died 21 Sept 1576 in Rome. Cardano is one of the most amazing personages connected with the revival of science in Europe and one of the most remarkable personality in a time surprisingly rich of extraordinaire celebrities and personalities; the Renaissance.

He was an extraordinaire Italian physician, the most famous European doctor of his time. Eventually he was acclaimed as the first diagnostician and outstanding therapist. He gave the first clinical description of typhus. His services were highly valued and requested in Italy and at the European courts, achieving many successes often remarkable (the Spanish Emperor Charles V, the Popes Gregorius XIV and Paul III, the King of Denmark, the King of France Francis I, his lientenant, Charles de Cossé, the regent Mary of Loren, the family of the Cardinal St. Charles Borromeo, the Cardinal Ercole Gonzaga, Duke of Mantua, the Archbishop of Scotland, James Hamilton, et al.).

Cardano was the most outstanding mathematician of his time and discovered the algebraic solution of the cubic. His book Ars Magna (1563)(The Great Art or The Rules of Algebra) is one of the cornerstone in the history of algebra. Cardano was an avid and at times compulsive gambler. His mathematic mind led to his mathematical study of gambling. He was the first to propound the mathematical theory of probability. He has been referred to as the “Gambling Scholar”. He was an inventor. He did important research in mechanics and hydrodynamics. He distinguished between electrical and magnetic activity. He invented several mechanical devices. The cardan-shaft, the mechanical device used in cars or motorcycles, was a Cardano’s invention.

He was a famous astrologer, highly regarded by his contemporaries and his horoscopes greatly requested. At that time astrology was completely respectable and more important than astronomy itself. The art of astrology needed a mathematical insight and a special education in astronomy. Many famous astronomer were astrologer too (Copernicus; Kepler; Brahe also alchemist). Cardano constructed horoscopes for outstanding personalities living and dead (Christ, King Edward IV of England, Petrarch, Vesalius, but also German personalities like Durer and Luther). Cardano was a natural philosopher, magician and sorcerer. He explored occult and, in some way, witchcraft and alchemy. He was a refined gourmet, a “must” for every Italian in every time, and investigated the secrets in cooking the different meals for achieving the best taste and flavour. He wrote and published more than two hundred books.

The warm friendship with the German “intelligentzia” started In 1539. Cardano was well known in Germany for his astrologic and mathematic writings. The distinguished Nuremberg publisher Johannes Petreius saw Cardano’s pamphlets and sent the astronomer and astrologer Georg Joachin Rheticus who was one of his agents, to seek the author out. The most famous work of Petreius was the original and celebrated edition of Nicolaus Copernicus’s “De Revolutionibus Orbium Coelestium” , after an initiative of Joachin Rheticus itself and Tiedemann Giese . Cardano was very interested to the offer of Petreius and in 1543 published the first booklet: “De astrorum judiciis” (Book of the judgement of the Asters), containing an amazing horoscope of Christ and a long and complicated calculation on the end of the world. Eventually Petreius published a long series of Cardano’s books, with the preface of the Lutheran theologian Andreas Osiander , living in Nuremberg and highly esteemed by Cardano. As is well known, Andreas Osiander played a prominent role in converting to the Lutheranism Albert of Prussia, Grand Master of the Teutonic Knights (1522) and to the adoption of Nuremberg to Lutheranism (1525). Petreius published in Nuremberg some famous books of Cardano. The “Ars Magna” (The Great Art or The Rules of Algebra) is a cornerstone in the history of algebra (1545) and the first treatise in academic Latin to survey the new Italian mathematics of the sixteenth century. The book contains a variety of methods for solving polynomial equations and anticipates the discovery of complex numbers. In 1550 Petreius published “De Subtilitate Rerum” (On Subtlety), an encyclopedia of 21 tomes. which was brought and translated in different languages. In France served as popular textbook on static and hydrostatic throughout the seventeenth century. These books were “best sellers” in Europe and Cardano became famous and celebrate, influencing the work of future mathematicians and scientists and playwrights as well. His book was translated into English and influenced Shakespeare. De Subtilitate Rerum is holding in hand of Hamlet at the beginning of the second act when Polonius asks to Hamlet what is he reading and he answer “words, words, words..”.

The treatises and commentaries not only on medicine or natural philosophy, but magic and astrology too reached an immense audience. In Catholic Europe but also in heartlands of Protestantism, like Wittemberg itself, the Cardano’s astrologic treatises were highly considered. Martin Luther made fun of the Cardano’s horoscope, explaining why he had rebelled against the Catholic Church. But Luther’s closest friend, Philipp Melanchthon , read Cardano with great care and thought it to the his students.

Cardano highly esteemed the German “Friends”. But after the Council of Trent and the Controriform, the politic and religious climate changed completely in the Catholic countries. The appealing friendship with the Lutheran “intelligentzia” became very dangerous and not without consequences.

The life of Cardano was amazing and unbelievable. Nothing he had been spared: the weighty and intolerable social prejudices, the more tremendous familiar tragedies, the furious and implacable lifelong hatred of the colleagues, economics disasters and poverty. Finally in his old age was imprisoned by the Inquisition. In 1570 Cardano was indeed accused for the heresy of casting the horoscope of Jesus Christ with the charge of “astrologic swear-word”, wrote in the booklet “De astrorum judiciis” , published by Petreius . The charge, that he had claimed astrological causes and not divine intervention as the force behind events in the life of Jesus Christ, was enough to land him in jail. Furthermore he wrote a book in praise of Nero, the great tormentor of the martyrs. And, last but not least, he was friend of outstanding Lutheran personalities who published and commented his books. It was clear for the Inquisition that Cardano was “too near and negatively influenced” by some ideas of the Reform. He was imprisoned for several months. In 1571 through the powerful intercession of very influential cardinals, Cardano was released, but was deprived of his professorship, prohibited from teaching and publishing any further. In 1571, on his release Cardano, old and ill, moved to Rome, where he received an unexpectedly warm reception by the Pope Gregorius XIII, who granted him a lifetime annuity, after first having been rejected by Pope Pius V.

Gottfried Leibniz summed up the man and his turbulent life when he wrote ”Cardano was a great man with all his faults; without them, he would have been incomparable”. The Cardano's life is the story of an man in a time of continuous cruel wars, the plague and lethal epidemics, a crucial revolutionary religion conflict (Luther, the Protestants and the Roman Catholic Church) and inquisitors and Spaniards busy in Italy. But he was above all else, human. “It is not the doctor in a long robe, who instructs us from the height of the pulpit: it is the human being” wrote Wolfgang Goethe . His life demands great interest and attention and inspires high respect and curiosity. Is the emblematic history of an European man of that time.