Venomous Astronomical Scorpio: Selected Aspects of Conflict between Galileo Galilei and the Jesuit Orazio Grassi

Markéta Ledvoňová


Medicean court philosopher Galileo Galilei is considered to be a symbolic founder of the scientific method exempt from the external influences. There's apparently no place for rhetoric in the „new science“, nor the usage of rhetorical fallacies. The paper is outlining the logic of background and adopted rhetorical strategies of Galileo's rarely surveyed treatise Il Saggiatore (Assayer), which is possibly one of the most evident testimonies against his persisting black-and-white image as an independent, exclusively rational scientist who expresses his ideas in the emotionless language of mathematics and geometry. The case of The Assayer however shows clearly that Galileo was also following the court manner and a man of the letters whose work was heavily influenced by the strict rules of patronage. The medicean mathematician was forced to defend himself and his patrons by any means in reaction to the book Libra astronomica ac philosophica by the Jesuit Orazio Grassi who verbally attacked Galileo behind the mask of the fictional student named Lotario Sarsi. Nevertheless, Il Saggiatore also served to promote the new rules for scientific research carried out by the members of  Accademia dei Lincei.


Galileo Galilei, Orazio Grassi, Assayer, patronage, fallacies

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Published by the Department of Philosophy, Faculty of Arts, Masaryk University, Brno, Czech Republic.
ISSN: 1212-9097