La scienza e l’ipotesi assoluta. Metodologia e logica della ricerca nell’Almagestumnovumdi Giovanni Battista Riccioli

Abstract

Astronomers before Newton in the 17th century attempted to find the best world system in the light of the new data and the novel observations that had been provided by the telescope but were not sufficient to prove that Copernicus was right. Using the new information, the Jesuit Giovanni Battista Riccioli developed a geo-heliocentric system that he considered a satisfactory alternative to heliocentrism. He argued that physical causes are difficult to generalize, but that nonetheless astronomers could formulate well-founded hypotheses. He skillfully combined the empirical data to articulate a deductive system, organized into elements such as definitions, arguments, theorems, corollaries, hypotheses, and so on. This system allowed him to avoid some of the errors of competing theories, and to obtain what he considered criteria to choose the best (hypothesis absoluta) using the so-called epic-epicycles. This article examines the conceptual and technical background of the Jesuit’s hypothesis and discusses how he was cautious yet bold in the way he formulated it.