I. Reputed shortcomings of Descartes as philosopher of science.II ‘Knowledge’ in mathematics and in physics. The ‘ontological’ postulates of Descartes's philosophy and philosophy of physics.III. The ‘foundations of dynamics’: ‘Newton's First Law of Motion’ and its status.IV. Descartes's conception of ‘hypothesis’: the competing claims of the ideal of the a priori in physics and the conception of retroductive inference. V. Descartes's notion of ‘analysis’. The distinction between ‘procedure’ and ‘inference’. The notion of ‘induction’ and ‘understanding through models’: ‘Snell's Law of (...) Refraction’. (shrink)