This book is an important revision to our understanding of the Lincean Academy, one of the earliest scientific societies, and the relationship between its founder, Prince Federico Cesi, and its most famous member. In particular, the author shows that Cesi was more a person of his times and that he and Galileo were less aligned than is generally presumed. The book concentrates on the period between 1611, when Galileo became a member of the academy, and 1630, when Cesi died; it thus ends before the publication of Galileo's Dialogue Concerning the Chief World System, and the subsequent trial.

Cesi founded the academy in 1603, dedicated to “a radical reform of received knowledge” (27) and convinced that “the alliance between the Catholic religion and the Aristotelian conception of the universe” was responsible “for the dramatic degeneration of knowledge and ethics” of his era (47). The prince was more interested in botany than in cosmology, but he was persuaded that the heavens were fluid and homogenous. This conviction came not from the heliocentric writings of Copernicus (which Cesi opposed because he was convinced that Copernicus believed in solid orbs) or the observations of Tycho Brahe; Galluzzi shows us that Cesi adopted such a conception because of the Neoplatonic writings of Bernardino Telesio. Repeatedly Galluzzi refers to Cesi's beliefs in astrology, alchemy, and natural magic as if they revealed Cesi's backwardness.

Did Cesi gain anything from his association with Galileo? Galluzzi maintains that after 1611 Cesi and his fellow Linceans “placed more emphasis on the direct observation of nature, on experimental practice and on mathematical speculations”; nevertheless, “these remained declarations of principle rather than models of research actually implemented” (59). In the latter part of the book, which focuses on Cesi's botanical researches, Galluzzi traces an increasing emphasis on the need for mathematics in the study of botany, which “seems in itself to attest the influence of the Tuscan scientist and to legitimize the definition of Cesi as a pioneer of quantitative botany” (423). Did Cesi have any influence on Galileo? According to Galluzzi, Cesi tried to get Galileo to tone down his criticisms of the Catholic Church, and of the Jesuits in particular. As we all know, that ended in failure. Galluzzi maintains Galileo “had to fight that battle in the name of the supreme value of truth and of his personal dignity”; he perceives in Galileo “the courage of truth and of confidence in the final triumph over the errors of pseudo-philosophy” (166). From Cesi's perspective that attitude was dangerous. Though Cesi, too, sought “freedom of thought in natural philosophy,” he tried to reach that goal by establishing “a reserved and protected space, the Lincean Academy, where, sheltered from the suspicions or censure of political and religious authorities, debates and research could be freely conducted” (341). Galileo's fight with the church threatened that protected space.

Galluzzi places Cesi “one step behind” Galileo in the advance of science (125), but while showing Cesi to be a man of the Renaissance, he presents Galileo as a man of the future. He writes about Galileo's relationship to astrology as if drawing up horoscopes was merely for his own “material benefits” (69), ignoring that Galileo also drew up horoscopes for himself and his family. He notes that Cesi pointed out the compatibility of Kepler's elliptical orbits with Galileo's requirement that nature's principles “appear elegant, simple and rational to our intellect” (119); Galileo insisted on circular orbits because he maintained that the natural motion of a sphere was circular, even if it required inelegant, complex, and irrational epicycles and eccentrics. Galluzzi also does not point out that Galileo's telescopic discoveries did not prove the Copernican system; they were equally compatible with Tycho's geo-heliocentric system. Moreover, while Galluzzi writes extensively about Galileo and tides, he is silent on Galileo's rejection of the influence of the moon on the tides. Galileo thought he could prove the earth's motion by the tides. He could not, but the “revolutionary principles of his new science of motion” (302) allowed others to disclose what Galileo failed to prove.