For those who find quantum mechanics "perplexing" or "troubling", it is beneficial to ponder the philosophical and historical origins of classical mechanics. (For example see the discussion of Hobbes below).
The _ground_ of modern physics was chosen and cleared during this period. Eventually Newton laid the _foundation_ of modern physics on this ground. Physics progressed by building on Newton's foundation. Whenever cracks have appeared in the foundation they have been patched, without a thought given to the condition of the philosophical ground. Harry From http://www.bu.edu/wcp/Papers/Mode/ModePiet.htm I. Conatus and Motion Philosophers in the 17th century made hard efforts to explain the beginning and continuation of the motion of bodies. The notion of conatus ('striving' or 'endeavoring') was commonly used in the explanations. It refers to the power with which the motion of a body begins and is kept on. What is this power? Descartes explained it to be an active power or tendency of bodies to move, expressing the power of God. He distinguished between motion and the tendency to move, but Hobbes was anxious to argue that conatus actually is motion. In The Elements of Law he says it to be the "internal beginning of animal motion" (EL I.7.2), and in his later writings the notion of 'endeavor' refers to the beginning or first part of any kind of motion. Because motion is for Hobbes "a continual relinquishing of one place, and acquiring of another" (De Corp II.8.10), the beginning of a motion of a body must be an infinitely small change in the place of the body. Accordingly, Hobbes defines endeavor "to be motion made in less space and time than can be given; ... that is, motion made through the length of a point, and in an instant or point of time" (De Corp III.15.2). For Hobbes, the conatus is not an inherent power of a body but is determined by the motions of other bodies. However, he regards it as an active power, because "the beginning of the motion of a body must be considered as action or cause" (De Corp II.9.6). Thus endeavor is the power by which a body affects the motion of other bodies and resists their power, and, in a sense, also 'causes' the motion of the body itself, for Hobbes takes the principle of the persistence of motion to be true: "whatsoever is moved, will always be moved in the same way, and with the same swiftness, if it be not hindered by some other moved and contiguous body" (De Corp III.15.1). Thus Hobbes, like Descartes and Spinoza, takes conatus to be the active power by which a body persists in its state of motion. In brief, Hobbes accepts the following fundamental principle: (CP) The conatus-principle: A body endeavors to preserve its state and resist the causal power of other bodies. This is a true natural law for Hobbes. I want to show the importance of (CP) for Hobbes's theory of human action and political philosophy. (more at link above.)
