ABSTRACT
The metaphysical roots of modern science lie in the mechanical philosophy of the seventeenth century (see Sarkar 1989 for a history). Central to that philosophy were two claims: (i) explanations of events must only invoke past events; and (ii) the behavior of bodies must be explained by the contact interactions of their constituent parts. A body gets hot, for instance, because of the increased motion of its parts; getting cold corresponds to a decrease of motion. Moreover, any motion of or within a body must be a result of motions imparted to the body or its parts by some other body in the past. Causal influences always move from the past into the future. Teleology (including Aristotle’s appeal to final causes) was illegitimate. Two types of locality were critical in causal interactions: spatial locality, because all interactions were contact interactions (there could be no action-at-a-distance); and temporal locality, which is implied by the fact that a contact interaction occurs only when cause and effect coincide in time. Longer chains of such primitive causal interactions allow one event to causally influence an event in a more distant future. Contemporary science does not call into question the mechanical philosophy’s first claim, the restriction of causes to those that emanate from the past, which amounts to an endorsement of Aristotle’s efficient causes as the only legitimate type of cause. The second claim, which we will call “compositionality,” is somewhat more controversial. It endorses what we now call “reductionism,” though, as we shall see, there are many twists to the story. The mechanical philosophy was immensely successful, allowing modern science to liberate itself from its scholastic shackles, but there always remained a recalcitrant skeleton it its closet. Ever since the publication of Newton’s Principia in 1687, the mechanical philosophers were faced with a superbly accurate theory – in fact the most quantitatively accurate theory yet seen in the history of science – that was based on action-at-a-distance, viz., Newton’s theory of universal gravitation. The eighteenth century saw many failed attempts to reconcile the mechanical philosophy with Newton’s theory of gravitation. Finally, in a somewhat desperate move in the mid-nineteenth century, Helmholtz weakened the mechanical philosophy to allow interactions governed by a central force (besides contact interactions).
