Today, we are at the dawn of the conquest of space, but the thousands of scientists working on these questions essentially share the same passion as the men and women who lived centuries ago.
Space fascinates millions of amateurs around the world, whether it is the discovery of exoplanets, the exploration of Mars or the hope of finding life elsewhere and we are witnessing the privatization of the conquest of space for results that no one can accurately assess.
In such a context, the general public might believe that these notions are specific to our current societies, but this is not the case. Centuries ago, this passion was already present in the hearts of many astrologers and astronomers. Astrology, which is none other than the belief in the influence on events (therefore the future) of terrestrial bodies by the position of the stars, has long been condemned in history, and this, since the councils and the Late Antiquity Church Fathers (for the Roman Empire) through Salic Law to Charlemagne and his heirs.
Today, astrology is considered a mere harmless superstition, while at the time, the church saw it as a dangerous means of questioning the divine will and the free will of man. If the beliefs around the stars were doomed, this was not the case for astronomy, a true science relating to the observation and understanding of celestial bodies. Throughout the Middle Ages, astronomy was even a kind of common core taught to university students.
Despite the errors of judgment made, astronomy was a driving force for knowledge. Indeed, if the roundness of the Earth was a common knowledge during the high Middle Ages after having long thought that it was flat, it was the model of geocentrism which was the norm (namely that of a round Earth around which the stars revolve). This vision will only be called into question during the Renaissance.
Astronomers study the movement of the stars and demonstrate it with geometric figures, calculate the lunar cycles to fix the date of festivals such as Easter, always with the aim of serving the church. Moreover, understanding these movements and establishing the rules governing the Universe gave credence to the dogma of divine creation, the harmony of which is then explained.

(Image credit: Astrologer Sylvie Tribut)
The West, however, lags behind in terms of progress and will take up many concepts developed in the Arab and Byzantine world after the translation of treaties into Arabic from the 12th century. Indeed, from the 8th century, the Abbasid caliphate of Baghdad financed the construction of many observatories, which already showed at the time the recognition of the sovereigns of these regions towards astronomers.
Thus, when we speak of the Middle Ages, it is absolutely necessary to make the difference between belief and science, therefore between astrology and astronomy. If the astrologers have good notions in astronomy, this serves them mainly to predict the future or practice medicine, as well as to advise sovereigns. Charles V is a very telling example since he granted unfailing credit there. Despite advances in astronomy and a condemnation of astral determinism by the bishop of Paris in 1277, astrology progressed during this period.
Today, scientists are doing research to try to understand the future potential of humanity and this is quite comparable to the way astrology used astronomy to do the same. Finally, wouldn’t all this be a matter of a certain belief in giving credit to the interpretation of scientific facts? Be that as it may, a document published in 2009 in the CNRS journal attempts to reconcile astronomy and astrology with the help of French astrophysicist Philippe Zarka.
Sources: Slate – CNRS