How Galileo Dedicated the Moons of Jupiter to Cosimo II de Medici

This article looks at the logic whereby in 1610 Galileo was able to change, from being the mathematics lecturer at Padua university to become the ‘court philosopher’ of Florence, following his discovery of the Jupiter-moons. Within the framework of Biagioli’s excellent account of these events, I argue for a slightly different perspective as regards why Galileo decided, or felt obliged, to dedicate the new moons to Cosimo II de Medici, in terms of a perceived astrological context to the event. I further suggest that a fuller appreciation of Galileo’s character is obtained by looking at the extent to which he shared the belief, widely accepted at the Medici court, of astrologically ordained destiny. By way of comparison, this article looks at nativities which Galileo cast for himself and for his Venetian friend, Sagredo, with his written commentary upon the latter. This work is developed in my ‘Galileo’s Astrology’.