How did Galileo’s science influence Descartes’s view of matter and motion?

Galileo Galilei’s pioneering scientific work significantly influenced René Descartes’s development of a mechanistic philosophy, particularly regarding the nature of motion and the physical world.

Galileo’s experiments with horizontal motion led him to deduce that a body in motion would continue to move indefinitely unless acted upon by an external force, such as friction. Descartes adopted and generalized this principle, establishing that bodies remain in motion in a straight line unless deflected by the impact of another body. This concept became a cornerstone of Cartesian physics, where all changes in motion are explained as the result of mechanical collisions.123

Furthermore, Galileo’s work helped shift the scientific perspective toward a universe that could be understood through mathematical physics and quantitative analysis rather than Aristotelian qualitative descriptions. Descartes embraced this mathematical approach, viewing the material universe as a plenum of matter governed by laws of motion that could be deduced through calculation. While Descartes utilized these ideas to construct a mechanistic model of the universe, he famously treated his own physical theories as "likely stories" to avoid the direct conflict with church authorities that Galileo had faced.45326