Aristotle and Descartes on Nature

Nature has been a key concept in Philosophy since Antiquity. Aristotle was the first thinker to prefer direct observation of natural phenomena to empty speculations on the possible influence of invisible deities on human destinies. For the author of History of Animals, each organism carries its own ‘biological’ determinism insofar as it is ‘programmed’ to carry out particular functions aimed at a specific purpose or telos. By refusing to pass judgement on the reasons behind the variations and vagaries of nature, Aristotle introduced the first empirical method of scientific enquiry, free from any religious connotation and relying exclusively on verifiable facts.

Challenging the views of nature inherited from both Aristotle and Aquinas (scholastic philosophy), Descartes formulated his purely rationalist conception, based on introspection instead of first-hand experience. Thus, Descartes showed no concern for what nature was ‘about’ but only for what men could do to become, as he famously put it, its ‘masters and possessors’. When Aristotle contrasted physics (the natural world) and techne (technical know-how), Descartes split the concept of nature into two distinctive and separate realms, namely, the realm of extended physical entities (res extensa) and the realm of pure thought (res cogitans). Because of its intrinsic lack of consciousness, nature – animals included – remained, for Descartes, condemned to a passive and inanimate form of existence as opposed to the self-reflecting ego. In this way, Cartesian subjectivity never comes into real or full contact with a doubtful external world but instead feeds its mind on its own concepts. Like his seventeenth-century contemporaries, Descartes saw in nature a life force which always demands respect but must eventually become subservient to the growing needs of a humanity showing a rising self-confidence in its intellectual capacities.