It is noteworthy that Georg Rheticus, a student of Copernicus, who most of all contributed to the spread and recognition of the heliocentric model, was an active practitioner of astrology and considered the heliocentric theory useful for astrologers.13
Nicolaus Copernicus with Hipparchus, Ptolemy, Galileo, Brahe, Kepler, Newton, Laplace
Galileo Galilei's Horoscope, Cast by Himself
Galileo Galilei, the great Italian mathematician, astronomer, and astrologer, practiced astrology throughout his entire or almost his entire career. For the 17th century, practicing astrology was common among educated people.14 The zealots of science often try to ignore this fact from the biography of Galileo, for example, through the assertion that he built horoscopes solely for the sake of money and denied the possibility of forecasting.15
However, the claims that Galileo denied the predictive power of astrology do not agree well with how carefully and in detail he built his own horoscope and the horoscopes of his daughters, for which he hardly received any money.16 Galileo's own horoscopes for February 16, 1564, 15:30, and 16:30 were published by the National Library of Florence in 1980.
The first interesting point in these horoscopes is the date of birth. Galileo's birthday is usually considered February 15 (according to the Julian calendar), but Galileo's horoscopes, which are "the sole source of evidence concerning his birthdate",17 indicate February 16.
The second feature of Galileo's horoscopes is that to the left of the charts, he wrote out the data required to calculate the primary directions, which are used to view the horoscope in dynamics and predict the course of life. This suggests that Galileo was quite serious about astrology and its predictive capabilities.
Galileo Galilei (1564—1642)
Johannes Kepler and the True Genealogy of Astrology
Kepler did not decry astrology but loved it.
It gave him the strength to know and be able to.
E.M.
Johannes Kepler, a scientific romantic, astrologer, and astronomer, one of the greatest learned men wrote in his book "Tertius Interveniens" ("Third-party Interventions", 1610)18 a paragraph that became one of his most famous quotes:
“Now, this Astrology is a foolish daughter. But dear Lord, what would happen to her mother, the highly reasonable Astronomy, if she did not have this foolish daughter. The world, after all, is much more foolish, indeed is so foolish, that this old sensible mother, Astronomy, is talked into things and lied to as a result of her daughter's foolish pranks… The mathematician's pay would be so low, that the mother would starve, if the daughter did not earn anything19.”
Kepler's quote about the "foolish daughter of astronomy" has been reproduced many times in his biographies and in articles blaspheming astrology. However, the meaning of the quote is not as simple as it may seem at first glance.
Johannes Kepler
Researcher Kenneth G. Negus has done a lot to restore the truth about Kepler's attitude to astrology. In his translation of excerpts from Kepler's books into English, he gave the following comment on the above excerpt from the "Tertius Interveniens":20
“It is important to note here that Kepler is referring to a particular kind of astrology ["this astrology"] and not all of astrology.”
To be convincing, the Negus lacked only a small touch – the words of Kepler himself about different kinds of astrology.
Indeed, Kepler distinguished popular astrology from genuine, as he called it. This is what Kepler wrote in 1627 in the preface to his famous "Rudolphine Tables", tables of planetary motions (ephemerides), compiled by him on the basis of Tycho Brahe's observations and the discovered laws of planetary motion:21
“Astronomy is the daughter of Astrology, and this modern astrology again is the daughter of Astronomy, bearing something of the lineaments of her grandmother; and, as I have already said, this foolish daughter, astrology, supports her wise but needy mother, Astronomy, from the profits of a profession not generally considered creditable.”
In the original text of the "Rudolphine Tables," the word Astrologia (the one that is "the mother of astronomy") is beautifully printed, with highlighted first and last letters. As for astrology which is "the foolish daughter of astronomy", it is written simply and plainly.
Kepler's biographer Max Caspar commented on this passage from the "Rudolphine Tables" as follows:22
“…the elderly mother (astrology) was not supposed to permit herself to complain of becoming abandoned and scorned by her thankless daughter (astronomy)”
In “Die Astrologie” Johannes Kepler wrote:23
“Philosophy, and therefore genuine astrology, is a testimony of God’s works and is therefore holy. It is by no means a frivolous thing. And I, for my part, do not wish to dishonor it.”
Kepler viewed the world as a manifestation of Divine harmony.24 At the heart of all his scientific work was the search for the harmony of the world – a pre-established order put into creation by the Lord God. Kepler set forth his own, very different from the generally accepted, astrology in the fourth book of his work "The Harmony of the World".25
Attempts to Deprive Ptolemy of Paternity over Western Astrology
Ptolemy. Engraving by Theodor de Bry (1596)
Some restless zealots of science go so far as to try to separate even the "father of Western astrology" Claudius Ptolemy, who lived in Alexandria of Egypt in the second century, from astrology, as from something "not prestigious" and "discrediting."
For example, astronomer and critic of astrology V. Surdin, who relies only on his own doubt which "originated a long time ago," questions that Ptolemy was an astrologer.26 He thinks that Ptolemy's wording is too accurate and careful to belong to an astrologer.
But even before Surdin, some "defenders" of science tried (unsuccessfully, however) to question Ptolemy's authorship of the astrological treatise Tetrabiblos. In this way, they tried to save “his authority as a scientist.27”
Popularizer of science Julius Alexandrovich Danilov (1936-2003), who was one of the translators of Tetrabiblos from Greek, wrote:28
“At the time of Ptolemy, the Greek words “astronomy” and “astrology” were almost synonymous, and what we now understand by astrology, Ptolemy called “prognostics,” that is, making predictions using astronomy. Practicing astrology did not cause the slightest damage to Ptolemy's reputation as a scientist and his authorship of "Tetrabiblos" was not considered a shameful secret. <…> Astrology did not lose its significance during the Renaissance, and later – at the beginning of Modern history.