The Catholic Church claims that its teaching about sex rests upon natural law. Germain Grisez, and his follower John Finnis, have developed a theory of natural law which supports that teaching and which they say is in Aquinas. In this book Steven Jensen challenges their work. He argues that they misinterpret Aquinas and that the theory they attribute to him is untenable in itself. It pretends to show that we can derive moral rules from certain precepts of natural law that are themselves derived neither from divine commands nor from theoretical knowledge, but which are self-evident to practical reason, known to be right independently of any other knowledge; and Jensen argues that the attempt fails. He does not explore the implications of his criticism for the Magisterium's sexual teaching, and though he attributes to Aquinas an alternative theory that enables us to derive moral judgments from theoretical knowledge of human nature, he leaves it to his readers to decide whether this alternative theory rules out contraception and other kinds of sexual activity contra naturam.
Jensen's scholarship in dealing with Aquinas is impeccable, and he backs his interpretations by an abundance of quotations in both English and Latin not only from the two Summae but from other works which are less widely known like the De Malo and De Veritate. This alone would make his book valuable. His argument against Grisez is ad hominem in character. Grisez accepts that we cannot reason from what is the case to what we ought to do, and also that our actions are caused by acts of will; they can be caused by commands, since commands, Grisez thinks, have a motive force derived from the will issuing them. But Grisez denies that his precepts are commands; he cannot, then, explain how they lead to action (pp. 215–8). Jensen also criticises Grisez and Finnis for postulating an indefinite plurality of things we ought to pursue, with no order of priority among them. Jensen is right, I think, that that is not Aquinas's position, and that Aquinas believes, though this is not spelt out in the central text for his natural law theory, Summa Theologiae 1a 2ae q. 94 a. 2, that they should be pursued only insofar as they lead to beatitudo, the Beatific Vision (pp.182-5).
Jensen defends the view that we can reason from what is the case to how we ought to act, and his positive theory is focussed, as he says (p. 7) on ‘the journey from “is” to “ought”.’ It is roughly as follows. We observe that we have natural inclinations to various objectives including those listed by Grisez. Recognising these objectives as ends, we think them good and desire for them, but these desires are imperfect and do not move us to act (p. 209). We consider which objectives to pursue here and now by relating them to the ‘ultimate end’, the good of the human being (p. 198), and when we see that in the present circumstances a particular course of action will achieve that good, our knowledge, from being only ‘virtually practical’, becomes ‘fully practical’, it ‘engages our will’ (p. 232), or becomes ‘the form of the will’, (p. 204), the desire becomes ‘fully fledged’, and we act.
Non-philosophers will agree that we reason from ‘is’ to ‘ought’, and Jensen presents his account of how we do this in tightly woven argument. He engages chiefly with writers who have written about Aquinas from a Catholic standpoint like Kevin Flannery, Ralph McInery and Martin Rhonheimer; other modern writers except for Philippa Foot are ignored. He has a straightforward, accessible style and provides plenty of examples. Nevertheless his exact line of thought is sometimes hard to follow. He starts (pp. 1–3) by speaking of the naturalistic fallacy, but he does not distinguish the real mistake, pointed out by Moore but irrelevant to his book, of confusing two questions, ‘What things are good?’ and ‘What does the word “good” mean?’, from the alleged mistake, which he holds to be no mistake at all, of moving ‘from is-statements to ought-statements’. He also omits to distinguish between the notion of goodness in a thing – the attributes that enable it to function well –and the notion of the good for something, the end for which it exists. Aquinas follows Aristotle in taking the good for human beings not as a set of attributes but as a kind of activity. Jensen uses the word ‘completion’ to cover both, and speaks oddly of good activity as ‘completing’ the agent. Jensen cites Aristotle only once, never mentions Plato and sticks to Latin words, but readers might have been helped if he had mentioned the Greek words aretê, ergon, entelekheia and energeia. There are also one or two points in his journey from ‘is’ to ‘ought’ about which he might have written more explicitly. Exactly how are the notions of goodness and an end related? Do we infer from the fact that we aim at something that it is good? If so, what does ‘good’ here mean? Or is having something as an objective the same as thinking it good? And how exactly does knowledge pass from being ‘virtually practical’, like knowledge how to make mayonnaise, to being ‘fully practical’, when according to Aquinas it is acquired or used (ordinatur) for that purpose? What role does Jensen give the will? He says it is ‘an efficient cause, moving to act’ (p. 216), and cites passages where Aquinas assimilates it to the fundamental forces of physical nature (p. 44; he might have added ST 1 q. 103 a. 8). The English word ‘will’ can mean simply ‘desire’ or ‘wish’, as in ‘Thy will be done’. Are we then moved to act simply by desire – desire, say, to please your family by making mayonnaise? Or must the will somehow step in and act before we carry out this desire? In that case, has it a will of its own? And is invoking it any better than Grisez's invocation of precepts of practical reason?
