 There is one mark of substance that was important to Aristotle that we have not discussed. This is the connection between substance and teleology; that is, the notion that what something is is intimately connected with its natural purpose, end or function. The association with teleology does not naturally recommend itself to the modern mind. Wiggins, for example, says that “it would have been both possible and advantageous for Aristotle to distance [his account of substance] from his concern with final causes…” (2001: 80). The concern with teleology is presumably thought to be too closely connected with Aristotle’s theology, or the idea that it is divine design or intelligence that gives natural objects their ends. Nevertheless, it is not easy for an Aristotelian to make a complete break from teleology. Teleology is what distinguishes living things that act for purposes and have organs with functions from lumps and rocks, and it is the former that Aristotelians see as the paradigm substances. It is no accident, therefore, that artefacts, which are generally defined by their function, are often cited as good illustrations—even if not paradigm cases—of substances. So we have a tension developing. On the one hand, lumps and rocks are good paradigm cases of our notion of natural enduring objects. But they are bad cases of objects with purposes or ends. Artefacts are good cases of things with purposes, and are reasonably enduring, but are not natural objects. Living things come near to getting the best of both worlds. They are natural and enduring, and they have purposes, in the sense of natural goals in their behaviour. (Although, according to the modern perspective they do not possess a final end, unlike artefacts: a knife is for cutting, but there is nothing a dog is for, though it has many ends en passant.)