Aquinas thinks of people as creatures with intellect and will, who are drawn to goals which attract them. For him, properly human action (actiones humanae), which he also calls 'moral action', is always a voluntary aiming for an end perceived as good. Since he thinks of goodness as perfective or fulfilling, this means that properly human action (or, as we may say, the moral life) is always a movement to what is fulfilling or perfecting of the agent whose movement it is. On Aquinas's account, people by nature desire or are attracted to what perfects and fulfils them, and in this fact lies the foundation of morality. 'Because in all things whatsoever there is an appetite for completion', he says, 'the final end to which each moves marks its own perfect and fulfilling good.' 1
But what is it that perfects and fulfils human beings? What is really good for them? To put it at its simplest, Aquinas's answer is that we are perfect, fulfilled, and good when we are happy. But to describe his position like that is indeed to simplify. In this chapter, therefore, we shall note its content insofar as he is chiefly speaking of people independently of Christian revelation. In the next chapter we will begin to see how he develops it with an eye on Christianity. Once again, I stress that I am not implying a twofold system in Aquinas. He never thinks of people without thinking of them as creatures loved by God and destined for union with him by virtue of Christ. But he has things to say about human action which do not, in his view, stand or fall by virtue of the truth of Christianity. And it is these things which concern me in this chapter.
In saying that human goodness lies in happiness, Aquinas does not mean that human fulfilment comes from doing whatever we happen