Intractable Disputes about the Natural Law: Alasdair MacIntyre and Critics

Chapter 7: Ultimate Ends and Incommensurable Lives in Aristotle

        Ultimate Ends and Incommensurable Lives in Aristotle Kevin L. Flannery, S.J. I. K  D In Will, Freedom and Power, Anthony Kenny sets out a very convincing understanding of the practical syllogism, according to which it functions quite differently from the standard syllogism. If a standard syllogism is of valid form, its premises give rise necessarily to the appropriate conclusion; if, on the other hand, a practical syllogism is set out as such a syllogism ought to be set out, its conclusion is defeasible (“defeatable”). As Aristotle understands the practical syllogism, the end sought appears as the major term, the means as the middle term (or middle terms), the action to be performed as the conclusion.1 In considering the various means that might take one, by way of a concrete action, to the end sought, all sorts of obstacles and alternatives might present themselves. To use Kenny’s  07 Cunningham Ch7 1/27/09 11:21 AM Page 227  | Kevin L. Flannery, S.J. own example, I may need to get to London from Oxford by : P.M., and decide quite reasonably to take the : train, but then recall that the : train is always crowded and not conducive to working during the journey; so I take instead the : train. Had I taken the :, my practical syllogism would have been valid as a practical syllogism, but it was reasonable too to change my mind. So there was nothing necessitating that conclusion; my original plan was defeated by further considerations .2 But, although Kenny puts this forward as an analysis of the Aristotelian practical syllogism, he maintains that it is incompatible with the understanding of happiness (that is to say, of eujdaimoniva) put forward not only by Aristotle but also by Thomas Aquinas: “Both Aristotle and St. Thomas sometimes write as if they thought that the first premise of a piece of practical reasoning must be a universal plan of life of this kind, specifying an all-embracing good. Indeed, the type of premise they had in mind was something not only universal, but also objective.”3 The problem, according to Kenny, lies not in the practical syllogism but in this objective, universal “all-embracing good”: “But whether or not the objectivity of the designated value refutes the Aristotelian theory of practical reasoning, the universality of the postulated major premises seems to me to establish the theory’s inadequacy .”4 Earlier in the same book, Kenny has said that “satisfactoriness,” which he regards as the key relation in the analysis of the practical syllogism ,“unlike truth, is a relative notion.”5 Here he is more expansive regarding this same notion: The defeasibility of practical reasoning comes about because of satisfactoriness being—like explanation—a relative notion: something is not satisfactory simpliciter, but satisfactory relative to a given set of wants; just as something is not an explanation simpliciter, but an explanation of a given set of data. The only way to avoid defeasibility in practical reasoning would be to insist that the premise setting out the goal should be not only cor07 Cunningham Ch7 1/27/09 11:21 AM Page 228 rect but also complete; that all the wants to be satisfied by one’s action should be fully specified. If we could do this, then there would be no danger of some further premise being added— some further want turning up—which would negate the satisfactoriness of the action described in the solution.6 According to Kenny, then, Aristotle and Thomas lighted upon the one way of invalidating their own theory. But Kenny is confused about where in the practical syllogism defeasibility has its bearing. Defeasibility cannot pertain to the end sought in a particular piece of practical reasoning, since an end is always fixed in the context of a particular piece of practical reasoning.7 It pertains rather to the means. Consider the very example that Kenny employs, that of taking the train to London. Let us say that I want to go to London in order to attend a lecture at :. Given that that is my end, many issues and alternatives might occur to me, but they all presuppose my desire to attend the seminar. Having reasoned perfectly validly that the : train is for me, that plan might be defeated by the thought that the : is always crowded, but what is defeated is that way of getting to London, not my desire to go to...