I have found just by learning a little about many things astrologically, tends to help in understanding and comprehending conversations with others. And if you find the topic interesting you can then delve deeper; I will list my sources in the references below in regard to the astrologer Johannes Kepler and his astrological work.
Johannes Kepler was born on the 27th of December 1571 in Weil within the Duchy of Wurttemberg part of the Holy Roman Empire. In the middle of this area was Stuttgart now part of modern day Germany. In 1576 upon his father and mother leaving for the Netherlands were his farther was to be posted in the army. Kepler then moved in with his grandfather to the town of Leonberg where he came down with smallpox. Because of his sickly disposition he set his mind to academic pursuits, and in 1583 started school. Upon completing his schooling, he enrolled at the university of Tubingen and upon gaining his MA in 1591 he accepted a position of lectureship in astronomy at Graz. The first paper he wrote was a sign of things to come, as it was on the primary motion of the earth and wasn’t based on mathematics and the copernicium system, but was philosophical and grounded in metaphysical notions. He had spent some time studying natures ebb and flow, the tides, rivers, winds, rain and the seasonal cycles. In many books written by astronomers and academics this mention is overlooked or ignored by choice, as these notions and observations by Kepler that inspired his first work are the staple of all good astrologers.
On the 27th of April 1597 Kepler married a spinster Barbara Muller and a year later moved to Hungary where he become acquainted with Tycho Brahe astrologer and mathematician to Rudolph the 2nd. Then in 1601 Kepler published (On The More Certain Foundations Of Astrology) this was his first attempt at giving astrology a more legitimate and respected footing. Then in 1606 he published (On The New Star of 1604) about the conversion of America, downfall of Islam, return of Christ. In 1610 he published again this time (In The Intervening Third Man, Or A Warning To Theologians, Physicians and Philosophers) In this he attempted to reiterate the middle ground between extreme views of astrology and explain his belief in a direct link between what happens in the heavens and what happens on earth. Barbra would die in 1612 ending an unhappy union. He most immediately set forth to look for a new wife and on the 30th of October 1613 he married again this time to 24 year old Susanne Reuttinger.
The notion that Johannes Kepler didn’t believe in astrology or vexed it in some way is quite ludicrous, but astronomers are repulsed at the thought of his use of it and admiration. It is true to say that he was a mathematician and scholar but not merely an astronomer. In truth he was for most of his professional life a practicing astrologer remembering that in his time astrologers and astronomers were really one and the same, but the astronomical measurements were not his primary source of income it was astrological almanacs and advice to his patron’s such as the holy roman emperor Rudolph the 2nd. Johanes Kepler maintained that he was driven against his own will in his belief of astrology as he had far too many unfailing experiences with it to ever doubt it. He did draw frustration at times on the amount of astrology he had to do to pay the bills this is true. As he was in fact furiously working on completing a catalogue of stars and planetary tables that would revolutionise the drawing of nativities. However, was limited for time due to the amount of almanacs and nativities he needed to produce for common purposes. While at his first posting at Graz he produced 4 annual almanacs , and in the first almanac he foretold of a bitterly cold winter and an invasion by the Turks, these both proved correct and helped his reputation from the onset. Kepler was believed to have said about the heavens: it does not endow a man with his habits, history, children, riches or a wife, but it moulds his condition. For me this statement as well as his use of astrology and comments he had made earlier lends me to believe that he was not a fatalist in the modern frame of thinking in his philosophical beliefs.
He published (The De Cometis Libelli Tres) in 1619 not an almanac but a publication full of predictions none the less. In 1619 Kepler also published, Harmonices Mundi (Harmonies of the world) it was inspired by Ptolemy’s harmonies theory 1500 years earlier and before writing it Kepler read Ptolemy’s work that was sent in manuscript form to him by the chancellor of Bavaria. Kepler discharged himself of all his duties and announced that he was free to give himself to the sacred madness and he was going to write the book. The premise was that the five regular solid figures had a kinship with the planetary spheres and musical tones the spheres being the mean motion of the known solid planets. Kepler completed the Rudolphine tables as I mentioned above using Tycho Brahe’s observations in 1623 and they were finally published at his own expense in 1627 due to disagreements with Tycho’s heirs as it was partly their inherited intellectual work. At the time they were his greatest achievement, a complete star catalogue and list of planetary tables much like todays ephemeris but far more accurate than any used before, they become a worldwide resource for astrologers to cast nativities and future astronomers to make observations. Kepler died on the 15th of November 1630 in Regensburg (now in Germany) of an acute disease. Overall there remains at least 800 nativities surviving that were drawn up by Johannes Kepler still in existence, some are his own or belong to his family others of his patron’s.
References for Johannes Kepler:
Harmonies Of The World (Johannes Kepler/Charles G Wallis) ISBN-1496085167
Kepler (Walter William Bryant) ISBN-1500439215
Great Astronomers (Robert Stawell Ball) ISBN-1374831948 or ASIN-B07VPS638L
A Brief History Of Western Astrology (Derek Parker) ASIN-B00FURCTWK
Astrology blog written by William Lamont Bellingen astrologer Australia on the astrologer Johannes Kepler.