Galileo, Descartes and Newton's Laws

The debate on the influence of Galileo in the formulation of Newton's laws in the Principia has naturally extended to the study of manuscripts from the period 1664-1684. Almost all scholars tend to minimize this influence and to highlight that of Descartes. However, Newton's texts show an original form of the first law and the definition of the vis insita that refer to the conception of a principle of conservation of motion as dynamic activity rather than a principle of inertia. This can be linked to the perspective of Galileo, which is in no way comparable to a conceptualization of inertia and which is bound to the ancient Greek philosophy of atomism. The inertial perspective manifested itself when the influence of Descartes on Newton prevailed over that of Galileo. Inertia is linked to the revival of an Aristotelian theme that favours the preservation of rest and that in the physics of Descartes and then of Newton would merge with the atomistic theme of the conservation of motion. Newton’s second law of motion drew on Galileo’s theory that the gravitational acceleration of falling bodies does not depend on their mass.