The biological basis of teleological concepts

What is the actual basis of terms such as "goal," "function," and "for the sake of"? Can these teleological concepts be validly applied to non-conscious biological processes such as the heartbeat, plant growth, and cellular metabolism? Does the behavior of any inanimate objects, natural or man-made, qualify as goal-directed? To resolve these issues, Harry Binswanger provides a unique approach combining factual and epistemological considerations. If human purposeful action is the paradigm case of goal-directed action, then regarding a non-purposeful process as goal-directed means taking it to be causally similar to purposeful action. Accordingly, to determine the proper extent of teleological concepts, Binswanger provides an analysis of purposeful action and a point-by-point comparison of the features of purposeful action to those of vegetative and inanimate processes. He concludes that natural selection, in adapting actions to ends with survival value, does make all living action qualify as goal-directed, and that no inanimate process qualifies. An appendix compares Binswanger's views with those of Larry Wright and Andrew Woodfield.