This essay develops a theory of natural signs in order to show how evolutionary theory breathes new life into teleology. An argument to the contrary presented by Richard Taylor is refuted. The essay defends the view that the concept of negative feedback explicates purposiveness and that symbiotic evolution explains the occurrence of naturally adapted feedback systems. But evolution itself is not a teleological process, nor is it a negative feedback system. There is an exploration of the nature of the dissatisfaction (...) we feel with an evolutionary account of purposiveness from which the fortuitous cannot be eliminated. (shrink)