We have been accustomed at least since Kant and mainstream history of philosophy to distinguish between the ‘mechanical’ and the ‘teleological’; between a fully mechanistic, quantitative science of Nature exemplified by Newton and a teleological, qualitative approach to living beings ultimately expressed in the concept of ‘organism’ – a purposive entity, or at least an entity possessed of functions. The beauty of this distinction is that it seems to make intuitive sense and to map onto historical and conceptual constellations in (...) medicine, physiology and the related natural -philosophical discussions on the status of the body versus that of the machine. In this presentation I argue that the distinction between mechanism and teleology is imprecise and flawed, on the basis of a series of examples: the presence of ‘functional’ or ‘purposive’ features even in Cartesian physiology; work such as that of Richard Lower’s on animal respiration; the fact that the model of the ‘body-machine’ is not at all a mechanistic reduction of organismic properties to basic physical properties but on the contrary a way of emphasizing the uniqueness of organic life; and the concept of ‘animal economy’ in vitalist medical theory, which I present as a kind of ‘teleo-mechanistic’ concept of organism – neither mechanical nor teleological. (shrink)