Five times in the extant corpus, Aristotle refers to a distinction between two ways of being a ‘that for the sake of which’ that he sometimes marks by using genitive and dative pronouns. Commentators almost universally say that this is the distinction between an aim (hou heneka + genitive) and beneficiary (hou heneka + dative). I propose that Aristotle had a quite different distinction in mind, namely: (a) that which holds between something and the aim or objective it is in the business of producing or achieving, and (b) that which holds between some instrument and the user of that instrument.
Gotthelf, A. (2012), ‘Aristotle’s Conception of Final Causality’ in Gotthelf (ed.), Teleology, First Principles, and Scientific Method in Aristotle’s Biology (Oxford), 1-44. [First printed Review of Metaphysics 30 (1976/1977), 226-54; also reprinted, with additional notes and a Postscript, in A. Gotthelf and J. G. Lennox (eds.), Philosophical Issues in Aristotle’s Biology (Cambridge, 1987), 204-42.]