Jerome Cardan


Jerome Cardan (or Cardano) of Milan, born in 1501, was a physician, mathematician, astrologer, philosopher and gambler. He was alternately poverty stricken and held in contempt, and rich, influential and admired. He was a prolific writer about many fields of endeavor. His found works fill 7,000 pages, however many of his works are believed to have been lost. He was ambitious, dishonest, hot-tempered, quarrelsome, conceited and humorless, but also capapble of being generous and kind. He suffered ill-health, both physical and mental.

He was a sickly and battered child whose mother made him feel unwanted. He helped his father who was a doctor in law and medicine by carrying his father's bag (imagine, house calls). At the age of 19, he entered the University of Pavia to study medicine. He settled in the little village of Sacco and gambled, played music, and took walks. Jerome describes this as the springtime of his life. He married at age 30 and had two sons. His favorite was executed for murder and his other son was a scoundrel who brought Jerome much sorrow.

Before Jerome was 50 years old, he was second only to Vesalius among European physicians and was healthy and wealthy. His fortunes began to fail when his favorite son, Giambatista, married a woman of ill-repute. Giambatista poisoned his wife with food sprinkled with arsenic. He was tortured and executed for this in 1560. Jerome Cardan never recovered from this tragedy. The disgrace of which put him in disfavor with all of high moral character. His second son gambled for outrageous stakes and was jailed at least eight times.

In 1570, Cardan was arrested for heresy, the causes of indictment have never been adequately explained but was probably the result of the counter-Reformation. Jerome was outspoken and had an opinion about everything. He was stricken from all roles of physicians and not allowed to practice. He went to Rome and gained leniency and membership in the College of Physicians. He had a limited practice and was paid a small pension by the Pope. He died in 1576.

Cardan had remarkable intuition about probability. His insights were written in a printed work of 15 folio pages called Liber de Ludo Aleae or "The Book on Games of Chance", a tiny gambler's manual that was not published until 1663 where the folio was embedded in a 10 volume edition of his complete works. This treatise formulated a number of fundamental probability principles, completed more than a century before Pascal and Fermat are supposed to have developed the theory of probability in their famous correspondence about the wagering problems.

In addition to his work in probability, Cardan made several advancements in algebra. In his greatest work, Ars Magna, Cardan broke an oath to Nicollo Tartaglia and published methods on solving cubic and quartic equations. Cardan also published 2 encyclopaedias of natural science, which contain a little of everything -- including the construction of machines, the usefulness of natural sciences, the evil influence of demons, the laws of mechanics, cosmology, and cryptology