It seems to me impossible to have the slightest doubt that Galileo was involved with astrology, indeed, that he was famous for his great ability in that art, so that distinguished people consulted him with complete confidence, in many cases asking for horoscopes and predictions. [1]

the chair of 'mathematics' then covered the teaching of geometry, astronomy, military engineering, and fortification. [4]

Astral Compulsion

Q: You said before that in the nativities that this Galileo makes, he calls his predictions certain; this is heresy. How then can you say that he is a believer in matters of faith?



A: I know that he said that and that he calls his predictions from the nativities certain, but I am not aware that this has been declared heresy. : You said before that in the nativities that this Galileo makes, he calls his predictions certain; this is heresy. How then can you say that he is a believer in matters of faith?: I know that he said that and that he calls his predictions from the nativities certain, but I am not aware that this has been declared heresy. [9]

The Qualities of Jupiter

So who does not know that clemency, kindness of heart, gentleness of manners, splendour of royal blood, nobleness in public functions, wide extent of influence and power over others, all of which have fixed their common abode and seat in your highness - who, I say, does not know that these qualities, according to the providence of God, from whom all good things do come, emanate from the most benign star of Jupiter? [11]

Jupiter, Jupiter I say, at the instant of Your highness's birth had already passed the slow, dull vapours of the horizon and was occupying the Midheaven, from which point it was illuminating the eastern angle, from that sublime throne saw the most happy delivery and all the splendour and magnificence of the newly-born diffused in the most pure air...

...in order that your tender body and your mind might imbibe with their first breath that universal influence and power, ...

If, therefore, of the inferior causes, those which arouse boldness of heart are diametrically contrary to those which inspire intellectual speculation, it is also most reasonable that the superior causes (if indeed they operate on us) be utterly different from those on which courage and the speculative faculty depend; and if the stars do operate and influence principally by their light, perchance it might be possible with some probable conjecture to deduce courage and boldness of heart from very large and vehement stars, and acuteness and perspicacity of wit from the thinnest and almost invisible lights. [13]

Dynasty and Destiny





Chart of Cosimo II de Medici. The Court Record Office gives 12th May 1590 at one in the night, i.e. one hour after sunset.[21] Sunset was at 7.06 p.m. that day (local apparent time), and Galileo's initial version of the chart I reconstruct as having been for 8.31 p.m., then his final vesion here shown, twenty minutes later, took 8.51 p.m. Galileo possibly used the later time in order to place Jupiter close to the Midheaven. A modern chartwheel using Regiomontanus house divisions plus the aspects formed by Jupiter (to Mars, Saturn and the ascendent) shows more clearly Jupiter's dominant position.



Charts for his Daughters

The Moon is very debilitated and in a sign which obeys. She is dominated by family relationships. Saturn signifies submission and severe customs which gives her a sad demeanour, but Jupiter is very well with Mercury, and well-aspected corrects this. She is patient and happy to work very hard. She likes to be alone, does not talk too much, eats little with a strong will but she is not always in condition and may not fulfil her promise.

Mercury rising is very strong for all things, and Jupiter which is conjunct gives knowledge and bounty, simplicity, humanity, erudition and prudence.

Giovanni Sagredo

The ascendent falls in the Terms of Venus in her own house, surrounded by the fixed Pleiades and applying to Jupiter by an exact sextile. She is free from rays malefic to herself.

From the combination of testimonies a warm and moist temperament results, indeed a sanguine one with lack of balance because of Venus being the ill-balanced lady of the geniture, and the ascendent and its house, and what is more from Saturn being in opposition to the ascendent.





Galileo's chart for Sagredo. The full worksheet, which offers interesting indications on Galileo's technique, can be found here.

And why do you leave out the prophecies of the astrologers ['genethliaci'], which are so clearly seen in horoscopes (or should we say in the configuration of the heavens) after their fulfilment? [24]

Galileo's Date of Birth





Two charts for Galileo's birth by himself, 3.30 and 4.00 p.m on February 16th 1564, published by Biblioteca Nazionale, Florence in 1980. Planetary longitudes are identical in the two charts (except for seven arcminutes for the Moon) and are also written out at the side, together with celestial latitudes.

[A larger image and notes on this chart can be found here.]



1564, 15 February, h 22.30. lat 42.30

16 February, h 4 pm

16 February, h 3.30 pm

I am astounded that Morino has such an extremely high regard for judicial [astrology] and that he claims with his conjectures (which to me appear uncertain, if not very uncertain) to establish the certainty of astrology; and it would really be a wonderful thing if - as he promises - he can, shrewd as he is, place astrology in the highest position of the human sciences; and I shall wait with great curiosity to see this marvellous innovation. [30]





Title page from Galileo's Sidereus Nuncius (Sidereal Messenger) printed in Venice, 1610.



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