 In this terminology, establishing that general principles are essential to moral reasoning leaves open the further question whether logically tight, or exceptionless, principles are also essential to moral reasoning. Certainly, much of our actual moral reasoning seems to be driven by attempts to recast or reinterpret principles so that they can be taken to be exceptionless. Adherents and inheritors of the natural-law tradition in ethics (e.g. Donagan 1977) are particularly supple defenders of exceptionless moral principles, as they are able to avail themselves not only of a refined tradition of casuistry but also of a wide array of subtle – some would say overly subtle – distinctions, such as those mentioned above between doing and allowing and between intending as a means and accepting as a byproduct. 