The concept of second nature plays a central role in McDowell's project of reconciling thought's external constraint with its spontaneity or autonomy: our conceptual capacities are natural in the sense that they are fully integrated into the natural world, but they are a second nature to us since they are not reducible to elements that are intelligible apart from those conceptual capacities. Rather than offering a theory of second nature and an account of how we acquire one, McDowell suggests that (...) Aristotle's account of ethical character formation as the acquisition of a second nature serves as a model that can reassure us that thought's autonomy does not threaten its naturalness. However, far from providing such reassurance, the Aristotelian model of second nature actually generates an anxiety about how the acquisition of such autonomous conceptual abilities could be possible. (shrink)