127

A precept of the law, since it is obligatory, concerns that which ought to be done. That something ought to be done, however, arises from the necessity of some end. Clearly, then, it belongs to the very notion of a precept that it implies an order to an end, insofar as that which is commanded is necessary or expedient for the end.’

2 I-Il 99,1- “Praeceptum legis, cum sit obligatorium, est de aliquo quod fieri debet, Quod autem aliquid debeat fieri, hoc provenit ex necessitate alicuius finis. Unde manifestum est quod de ratione praecepti est quod importet ordinem ad finem, inquantum scilice illud praecipitur quod est necessarium vel expediens ad finem. »

132

In general, then, ought-statements identify what belongs to a thing in itself, when that possession is not yet realized (it is to be), so that in some sense the possession is “owed.” The particular kind of ought-statements with which we are concerned involve some necessity from an end. “Louis ought to turn right at Louisiana Street” expresses what belongs to him precisely insofar as he has an end of getting to the opera. Unlike Kant, Aquinas believes that moral precepts belong to this subset of ought statements.

139 The good is a kind of final cause; it is that which completes an inclination. We recognize this causality through its effect; therefore, we define the good in terms of its effect, so that the good is the object of desire.