ABSTRACT
It is tempting to view references to the potentialities and powers of bodies in mechanical treatises of the early seventeenth century as vestigial traits of a natural philosophy not yet fully distinguished from its Aristotelian progenitors. Such references seem at odds with an assumption, widely held among early critics of the new mechanical philosophy, that in its insistence that all material things are configurations of inertial bits of matter colliding aimlessly with one another, mechanism eradicated all inherent powers and activity from nature. 1 The alleged erosion of active and passive powers from physics was part of a general undermining of the influence of Aristotle and of the idea that each kind of thing could be characterized by its potentiae, powers to cause change and potentialities to undergo change. One problem that the Aristotelian notion of active powers was designed to solve – accounting for the starting point and direction of change – remained, however, and the mechanists’ idea that bodies exhibit law-governed tendencies or “strivings” (conatus) to move in a certain direction restored something of this original idea. As the natural expression of these strivings in organic systems, the passions held the key to ousting Aristotelianism from the one domain of natural philosophy where its authority appeared unquestionable – biology. Theories of the passions proliferated in the seventeenth century less from a natural curiosity in the subject than from a pressing need to demonstrate the completeness of mechanism as a science of nature.
