Abstract
The full compliance assumption has been the focus of much recent criticism of ideal theory. Making this assumption, critics argue, is to ignore the important issue of how to actually make individuals compliant. In this article, I show why this criticism is misguided by identifying the key role full compliance plays in modelling fairness. But I then redirect the criticism by showing how it becomes appropriate when Rawls and other ideal theorists expect their model of fairness to guide real-world political practice. Attempts to establish institutions conforming to this ideal could have undesirable consequences and might even undermine fairness itself.