It may seem that we have already answered this question. Hasn’t the argument in the previous Article already shown that man’s property of acting for an end is due to his rational nature? No, for that argument showed only that man’s manner of acting for an end – his dominion over his deeds – is due to his rational nature: He acts toward ends and knows what his ends are. Could it be that in some sense, creatures that lack reason will also act for an end? The tradition has held that they do – that all things in nature are directed to ends, even among the lower creatures that do not know what they are doing. St. Thomas seeks to find out whether this is true.

If we are speaking of the incomplete happiness of this life, then it is obvious that one can have more or less of it than another. But that is not the question, for we are speaking of the complete and consummate happiness that leaves nothing to be desired. Is it possible for someone to have more or less of that? Most often for the reason expressed in the second Objection, most people have difficulty imagining how this could be the case. Can there be degrees of what cannot be improved?

In the previous Article, St. Thomas made it clear that different men might pursue different ends as though they were ultimate. Now he considers whether such differences arise from a mistake: Whether, despite disagreements about what the ultimate purpose is, in some sense all people are aimed at the same one – even if they err about what it is.

In one sense, we have already considered the attainment of happiness, for in Question 4 we investigated the requirements that must be fulfilled in order to have it. This turned out to be a more complex question than might have been expected, because there is more than one sense in which a thing can be required for happiness. For example, it may be required in the sense that happiness cannot exist without it, or merely in the sense that it is one of its concomitants.

In the previous Article, St. Thomas showed that no human being can achieve supreme happiness by his own natural powers. However, during the course of the argument he maintained that man can achieve supreme happiness by the power of God. Someone might ask: Is God our only resort? Even if our own powers do not suffice, can we attain supreme happiness by any power superior to ours, but short of His? In particular, might we have assistance from the noncorporeal intellectual creatures that the tradition has called angels?

The intellectual powers include reasoning and understanding, but they also include will. To will is to desire something because it seems good to the mind rather than to the senses: It is rational appetite, not just sensitive appetite. So if happiness really does pertain to our intellectual rather than sensitive powers, is it a matter of understanding, or of rationally desiring?

St. Thomas frames his arguments in such a way as to apply to all bodily goods. However, he has the Objectors focus on the bodily good of health, and with good reason. Only a few people think supreme happiness lies in swiftness. Perhaps a somewhat larger number think it lies in beauty. But a great many think it lies in health.

Can we acquire supreme happiness by our natural abilities alone? The problem is more subtle than it appears. Perhaps the answer is “Yes”; perhaps “No,” on grounds that we need supernatural help. But if “No,” then in what sense can happiness be considered our nature’s fulfillment? Wondering how the popular culture answers St. Thomas’s query, while writing about this Article I performed a quick web search using the question “What can we do to be happy?” The first time I ran the search, the query yielded 627 million hits.

As I explained in the Introduction, the Angelic Doctor does not write like the author of a mystery story. He has been providing what mystery fans call “spoilers” for quite a while. Finally we reach the pivotal question, the one to which the spoilers have been pointing: Are we really united with God by knowing Him, and is this really our happiness?

It might seem that whether happiness is possible after the deaths of our bodies is a matter of concern only to Christians. In St. Thomas’s view, not so. For reasons explained in the Discussion, he believes that the immortality of the soul is not only a teaching of the Christian faith, but a bona fide conclusion of reason, so even non-Christians should believe it. If this truth was not entirely clear to pre-Christian philosophers (and it wasn’t), the reason is not that they could not have discovered it, but that even though they could have, they simply didn’t. What does come uniquely from faith is the doctrine of the general resurrection: That after a period of time, the separated souls of the dead will be reunited with their bodies.

St. Thomas is sometimes disparaged for having supposedly merely retraced Aristotle’s discussion of where supreme happiness lies. Sometimes it is even claimed that he and Aristotle arrived at the same answer: Contemplation. Let us take these two criticisms in turn.

If few universities today have departments of angelology, the reason is that few scholars today believe in immaterial, personal substantial beings distinct from God. Even many who do believe in God consider angels a sort of fairy tale. It is curious that persons who believe in God and believe in man would consider it impossible that God would create any rational beings higher than we are. Yet this is the prejudice.

To ask whether delight is required for supreme happiness is to ask whether any so-called happiness that did not include the element of delight could be completely happy. This is not the same as asking whether happiness lies in delight; in Question 2, Article 6, that query was answered in the negative.

As remarked before, the expression “speculative intellect” is grossly misleading in English, and the expression “theoretical intellect” is not much better; this intellectual power has nothing to do with guessing or even with concocting theories. The reason the expressions came into use is that their respective Latin and Greek roots refer to having a view of things. So we might say that as the practical intellect is the guiding or doing mind, the speculative intellect is the seeing or knowing mind.