Life and Force

This chapter highlights an important analogy between life and force. Just as Leibniz invokes force to account for the phenomena of motion in physics, in his life sciences he invokes the soul (or anima or entelechy) that must be presupposed as the ground for the phenomena of life. Indeed, Leibniz’s motivation in invoking the notion of a natural machine is precisely to limit the extension of mechanical philosophy and draw a line between living and nonliving things. This distinction does not turn primarily on physiological grounds but, rather, involves metaphysical considerations. Likewise, both the notion of force and the source of life, according to the author, must be understood metaphysically. In both cases, these metaphysical principles are supposed to be compatible with a mechanical explanation of the phenomena of life. Nevertheless, the principle of life is a metaphysical principle that cannot be observed; only its consequences, the phenomena of life, are observable.