Una nuova edizione del "Saggiatore"

In this paper, we set out the main reasons that led us to prepare a new edition of Galileo’s Saggiatore (1623), the work that originated from a dispute with the Jesuit mathematician Orazio Grassi on the nature and motion of comets that appeared in the second half of 1618. Above all, we emphasise an aspect, almost always ignored by Galilean historiography, namely the hypothetical character that Galileo attributes to his own cometary theory. Finally, in the concluding part, we expound the elements that distinguish our edition from previous ones.