This paper aims to show that the seventeenth-century conception of mechanics as the science of particles in motion founded on universal laws of motion owes much to the employment of a new conceptual resource – the physics of motion developed within optics. The optical analysis of reflection was dynamically interpreted through the mechanical analogy of rebound. The kinematical and dynamical principles so employed became directly applicable to natural phenomena after the eventual transformation of light's ontological status from that of an (...) Aristotelian ‘quality’ to a corpuscular phenomenon, engendered by the rise of atomism during the first half of the seventeenth century. The mechanization of light led to a conceptual shift from the analogical employment of dynamical principles in the physical interpretation of reflection to the mechanical generalization of optical principles – the direct application of kinematical and dynamical principles of reflection to mechanical collisions. This first part of the paper traces out the first conceptual shift from Aristotle's original analogy of reflection as rebound to its full concretization. A second part will trace out the second conceptual shift, from the full concretization of this analogy to the axiomatization of already generalized kinematical and dynamical principles of reflection into laws of nature and of motion. (shrink)

This paper argues that, contrary to the claims of Alan Chalmers, Boyle understood his experimental work to be intimately related to his mechanical philosophy. Its central claim is that the mechanical philosophy has a heuristic structure that motivates and gives direction to Boyle's experimental programme. Boyle was able to delimit the scope of possible explanations of any phenomenon by positing both that all qualities are ultimately reducible to a select group of mechanical qualities and that all explanations of natural phenomena (...) are to be in terms of the operations of machines and are to appeal only to qualities that are already familiar. This is illustrated by his investigations into the Torricellian experiment. Boyle's explanation of the elevation of the mercurial cylinder by appeal to the spring of the air was an intermediate mechanical explanation. Boyle was convinced that the spring of the air was ultimately reducible to the mechanical qualities. This in turn had implications for his research into the cause of respiration. In a move that was both parsimonious and consistent with the broad requirements of the mechanical philosophy, Boyle was able to solve the problem of the cause of the inflow of air into the lungs by appeal to his research in pneumatics. This application of a mechanical explanation in pneumatics to physiology is just what one would expect if the mechanical philosophy was as universal as Boyle claimed it to be. Therefore, far from Boyle's experiments having a life of their own, they were clearly directed by and understood in terms of the mechanical philosophy.Keywords: Air-pump; Boyle; Chalmers; Experiment; Explanation; Mechanism. (shrink)