Yashar of Candia—Rabbi Joseph Solomon Delmedigo היש"ר מקנדיאה — רבי יוסף שלמה דלמדיגו

Born on 16 June 1591 at Candia—today Heraklion, then Venetian—and died on 16 October 1655 at Prague. A descendant of Elijah Delmedigo, the fifteenth-century Averroist. At Padua he studied from 1606 to 1613: medicine, philosophy, astronomy, mathematics. In the academic year 1609–10 he attended Galileo's lectures and used his telescope.

Then Venice and the circle of Leone Modena and Simone Luzzatto; Egypt, where he held a public mathematical disputation with the Arab scholar Ali ibn Rahmadan; Constantinople, where he bought Karaite manuscripts and observed the comet of 1618–19; from 1620 Vilna, as physician to Prince Radziwiłł; then Hamburg, Amsterdam, Frankfurt and Prague.

Elim was printed at Amsterdam in 1629 by Menasseh ben Israel. The book is strangely and admirably built: answers to twelve major and seventy minor problems posed by the Karaite Zerah ben Nathan of Troki. A Rabbanite conducts a years-long scientific correspondence with a Karaite, and a Sephardi rabbi in Holland prints it.

What he introduced: heliocentrism—and he was the first Jewish scholar to use logarithmic tables, published by Napier only fifteen years before.

His position on Kabbalah is deliberately unstable. At eighteen he mocked it; at twenty-seven he shifted, having met scholars who showed him its likeness to Platonism. Matzref la-Hokhmah ostensibly refutes his own ancestor's anti-kabbalistic Behinat ha-Dat—but he wrote, "do not presume that you can unravel the author's mind from his book," and Leone Modena read the same work as covertly anti-kabbalistic.

Two corrections. "Galileo's student" is too strong: one academic year of lectures and the loan of a telescope; and "rabbi Galileo" in his usage means "my master," not a title. "Spinoza's teacher" is a scholarly thesis about influence through books: Spinoza was born in 1632, long after Delmedigo had left Amsterdam, so direct instruction is impossible. And Elim went to press truncated: of the twelve major problems only four were printed.