A scholar of many interests, with a solid knowledge of medieval and humanistic natural philosophy, Chiaramonti organised a "Lyceum" at his house, in which he taught mathematics, optics and perspective.

Chiaramonti was such a determined defender of classical astronomy that he rejected even the Tychonic system, which was by then commonly accepted among Jesuit scholars and other astronomers who did not agree with the views of Copernicus.

[5] Despite the fundamental difference of views with Chiaramonti, Galileo maintained cordial relations with him at this time, referring to him positively in The Assayer as having conclusively proved the falsity of Tycho's model of the universe.

The poet Pier Francesco Minozzi praised him in verse as ‘the Aristotle of our times.’[1] In 1627 Chiaramonti was elected to the chair in philosophy at the University of Pisa with an annual salary of 700 ducats,[1] where he remained until 1636.

[2][6] In 1629 he applied to the more prestigious university of Bologna to teach mathematics, but his appointment was blocked, with particularly strong opposition from Galileo's friend Cesare Marsili, who described him as "such an enemy of astronomers" ("tanto nemico degli astronomi").

In the dialogue, arguments that he had used in past were placed in the mouth of Galileo's idiot character Simplicius in such way that, as Chiaramonti himself commented, only a "scempio" ("disgrace", "total mess") like Simplicio could possibly believe them.

The character of Salivati firmly rebuts these points, dismissing "Antitycho" as a work hardly meriting serious attention, and referring to existence of sunspots, which not only darken the surface of the Sun, but cast a shadow on the whole of peripatetic philosophy.

[10][11] In a letter to Élie Diodati on 25 July 1634 Galileo complained that in the Difesa, Chiaramonti had allowed himself to be drawn into writing 'exaggerated' and 'reckless' things which, outside of present circumstances, could easily have been refuted.

[1] In 1635 Chiaramonti published a work of political philosophy, Della Ragion di Stato which examined at great length different possible definitions of the terms 'reason' and 'state' and considered the dilemmas of statecraft and morality.

As he died soon after, this allowed Chiaramonti the last word, which he took with a volume of more than 500 pages, summarising his Aristotelian positions on a wide range of topics, his Opus Scipionis Claramontis Caesenatis de Universo (1644).

While pursuing these extended arguments, Chiaramonti produced a number of systematic treatises which reaffirmed classical Aristotelian thinking, and in 1643, the year after Galileo's death, he published an attack on his views in Antiphilolaus.