Introduction: A summary of the argument
Introduction supernatural matters . . . By hope and charity the will acquires a certain tendency towards that supernatural good' (ibid.).
A summary of the argument Early in this introduction I stated my conviction that Aquinas's moral theory is so systematically unified that no single discussion – whether of the human good, the natural law, the nature of responsible action, or the virtues–canclaimprideofplace.Afulldefenceofthisclaimwouldrequire awholebook,butbynowIhaveatleastsketchedenoughoftheconnections to make the claim plausible. I want to conclude by summarising my line of argument. The doctrine of natural law identifies and characterises the ends that are presupposed by all genuinely human agency. As Aquinas explicitly says, 'the precepts of the natural law . . . are the first principles of human acts' (aae .ad ). Those precepts provide the necessary anchor for practical reasoning. That anchor is not explicitly identified when Aquinas comes to discuss the nature of responsible action, but it must be assumed if that discussion is to make sense. For while Aquinas's action theory clearly recognises that all action and all practical reasoning must rest on ends that are objects of both cognitive and appetitive powers, it does not offer us any account of what those ends are; nor does it explain how those ends come to be either known or desired. Without the theory of naturallaw,therefore,Aquinas'sactiontheoryislargelyempty;itcertainly does not contain all the materials needed to generate a normative ethical view.
But the theory of natural law cannot stand on its own either. Without the accounts of human agency, practical reasoning, and the virtues, natural law theory would offer us only a somewhat sketchy philosophical anthropology, not a fleshed-out ethics. The fleshing out happens only when Aquinas takes the general account of the human good provided by natural law theory and shows how it can be concretely realised by individual human beings through the use of practical reason to shape not only particular purposive actions but patterns of action and reaction. In order to do this, human beings must acquire dispositions – the virtues – that enable them to act readily, reliably, and with pleasure in ways that accord with their overall good. That good in turn is twofold. There is both a natural and a supernatural good, each with its own virtues. But even the supernatural good bears an intelligible relation to the natural, and the xxix
Introduction virtues by which we attain it have a structure parallel to that of the virtues by which we attain our natural good. Thus, even that aspect of Aquinas's ethics that one would expect to stand apart from the rest turns out to be thoroughly integrated with his whole system, as befits a thinker who holds that 'grace does not destroy nature, but brings it to fulfilment'. The theory of natural law, therefore, turns out to be a perfect springboard into a theory of supernatural virtue. xxx