During the years from 1616 (when the Decree prohibiting
two Copernican propositions was issued by the Congregation of the Index) to 1623 (when Galileo published The Assayer) Jesuits of the Roman College made several attempts to draw Galileo into further discussion of his work. This was not with the intention of checking his obedience to the Decree, but in order to test the strength of any continuing work. The evidence suggests that there were certain Jesuits, who were willing, even determined, to re-open debate with him. They made a genuine attempt to build a new synthesis, aligning the established world picture with some of the new astronomical observations. The initiatory moves in these attempts, always made through a third party, ranged from the oblique to the overtly demanding.
As early as 1614 a group of Jesuits at Ingoldstadt saw problems in the way the new astronomical discoveries could be used by those interested in magic and astrology, and asked Aquaviva the General of the Society of Jesus to prohibit one of their members from writing in praise of Galileo's work. From this initial move against the Galilean findings, there stemmed a reactionary group which led to a reaffirmation of the primacy of the Aristotelian cosmology, in the Roman College in 1624.
With the Ludovisi Papacy, initiated by the election of Cardinal Ludovisi as Pope Gregory XV there emerged a lighter, more buoyant intellectual atmosphere, one in which Pope and Cardinal Nephew played a leading role. This change in Papal outlook caused Galileo to think there was the possibility that the severity of the 1616 Decree might be lessened, and as a consequence his long-promised book The Assayer was completed and appeared in manuscript early
in 1623. During the time of its printing Gregory XV died and
Maffeo Barberini became Urban VIII, and though this seemed to offer even better possibilities for Galileo, in the event there were to be greater problems ahead.