Abstract

According to some currents of modern historiography, Galilei's propensity for circular motion would have led him to consider this and not rectilinear motion as “natural motion”; therefore the principle of inertia could not be fully attributed to Galileo, which he would never have formulated. The question of the authorship of the principle of inertia certainly weighs on both nationalistic elements and returns of antigaleleism, while the question of its not explicit formulation as a principle is due to ignorance of the type of organization that Galileo intended to give to the exposition of his physics. The author, after having hinted at possible prodromes of the principle of inertia and having reported the adverse opinions of illustrious historians of science (A. Koyré, I. B. Cohen, P. M. Duhem, P. Rossi, G. Holton), through a careful analysis of the Galilean writings, conducted on the digital versions with the help of text analysis programs, firmly reaffirms Galileo's authorship of the principle of inertia and the consequent principle of classical relativity.