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3 Kepler and Astrology
Kepler disdained astrologers who pandered to the tastes of the common man without knowledge of the abstract and general rules, but he saw compiling prognostications as a justified means of supplementing his meagre income. Yet, it would be a mistake to take Kepler's astrological interests as merely pecuniary. As one historian, John North, put it, 'had he not been an astrologer he would very probably have failed to produced his planetary astronomy in the form we have it.'
Kepler believed in astrology in the sense that he was convinced that astrological aspects physically and really affected humans as well as the weather on earth. He strove to unravel how and why that was the case and tried to put astrology on a surer footing, which resulted in the On the more certain foundations of astrology ( 1601), in which, among other technical innovations, he was the first to propose the quincunx aspect. In The Intervening Third Man, or a warning to theologians, physicians and philosophers ( 1610), posing as a third man between the two extreme positions for and against astrology, Kepler advocated that a definite relationship between heavenly phenomena and earthly events could be established.
At least 800 horoscopes and natal charts drawn up by Kepler are still extant, several of himself and his family, accompanied by some unflattering remarks. As part of his duties as district mathematician to Graz, Kepler issued a prognostication for 1595 in which he forecast a peasant uprising, Turkish invasion and bitter cold, all of which happened and brought him renown. Kepler is known to have compiled prognostications for 1595 to 1606, and from 1617 to 1624. As court mathematician, he explained to Rudolf II the horoscopes of the Emperor Augustus and Mohammed, and gave astrological prognosis for the outcome of a war between the Republic of Venice and Paul V. In the On the new star ( 1606) Kepler explicated the meaning of the new star of 1604 as the conversion of America, downfall of Islam and return of Christ. The De cometis libelli tres ( 1619) is also replete with astrological predictions.
4 Kepler on God
"I was merely thinking God's thoughts after him. Since we astronomers are priests of the highest God in regard to the book of nature," wrote Kepler, "it benefits us to be thoughtful, not of the glory of our minds, but rather, above all else, of the glory of God."
5 Writings by Kepler
- Mysterium cosmographicum ( The Cosmic Mystery ) ( 1596)
- Astronomiae Pars Optica (The Optical Part of Astronomy) ( 1604)
- De Stella nova in pede Serpentarii (On the New Star in Ophiuchus's Foot) ( 1604)
- Astronomia nova ( New Astronomy ) ( 1609)
- Dioptrice ( Dioptre) ( 1611)
- Epitome astronomiae Copernicanae (published in three parts from 1618- 1621)
- Harmonice Mundi ( Harmony of the Worlds ) ( 1619)
- Tabulae Rudolphinae ( 1627)
- Somnium (The Dream) ( 1634) - considered the first precursor of science fiction.
