David Charles on Teleological Explanation in Aristotle

Reference: David Charles, "Teleological Causation in the Physics," in Lindsay Judson, ed., Aristotle's Physics: A Collection of Essays (Oxford, 1991), pp. 101-28).

Charles argues that Aristotle's discussion is neutral or ambiguous between, and in fact runs the risk of conflating, two models of teleological causation:

Purposive Agency Model

Example: Socrates walks after dinner to achieve healthy digestion.

  • (i) A values G (or, G is a good for A);
  • (ii) M is a means to G; and
  • (iii) A chooses M because M is a means to G.


  • (i) Socrates values healthy digestion;
  • (ii) Walking after dinner is a means to (causes) healthy digestion;
  • (iii) Socrates chooses to walk because he accepts (ii).

    Note the role of conscious valuation or perception by the agent in (i) and (iii).

    Functional Model


    Camels have multiple stomachs in order to digest their thorny food.

    Natural entity N has organ O for the sake of the function (natural end or goal) F iff:

    Note there is no role for choice or the agent's perception of a good in this analysis.

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