Encyclopedia of Philosophy: Aquinas' Moral Philosophy

« From remarks such as this Aquinas' followers developed the famous doctrine of double effect.

If an act, not evil initself, has both good and bad effects, then it may be permissible if (1) the evil effect is not intended, and (2) thegood effect is not produced by means of the bad, and (3) on balance, the good done outweighs the harm.

Thereare many everyday applications of the principle of double effect: e.g.

there is nothing wrong with appointing thebest person to a job, though you know that by doing so you will give pain to the other candidates.

The principle isfundamental to serious ethical thinking; but for reasons to be discussed later, it fell into disrepute among moralistsin the early modern period.In the Secunda Secundae Aquinas analyses each individual virtue in turn, and the vices and sins which conflict withit.

Here, too, he is following Aristotle; but there are important additions and modifications.

Christian tradition hadadded the three ‘theological' virtues of faith, hope, and charity to the classical Greek list of wisdom, temperance,courage, and justice.

Aquinas accordingly treats of the virtue of faith and the sins of unbelief, heresy, andapostasy; of the virtue of hope and the sins of despair and presumption; and of the virtue of charity and the sins ofhatred, envy, discord and sedition.Aquinas' list of moral virtues does not altogether tally with Aristotle's, though he works hard to Christianize some ofthe more pagan characters who appear in the Nicomachean Ethics.

For Christians, for instance, one of the mostimportant virtues is humility.

Aristotle's good man, on the other hand, is far from humble: he is great-souled, that isto say he is a highly superior being who is very well aware of his own superiority to others.

In his treatment ofhumility, Aquinas comments on the text of St Paul, ‘let each esteem others better than themselves'.

How can thisbe possible, and if possible, how can it be a virtue? Aquinas sensibly says that it cannot be a virtue to believeoneself the worst of sinners: if we all did that, then all but one of us would be believing a falsehood, and it cannotbe the part of virtue to promote false belief.

He glosses the text thus: what is good in each of us comes from God;all we can really call our own is our sinfulness.

But humility does not require, he says, that someone should regardless the gifts of God in himself than the gifts of God in others.Aquinas defines humility as the virtue which restrains the appetite from pursuing great things beyond right reason.It is the virtue which is the moderation of ambition – not its contradiction, but its moderation.

It is based on,though it is not identical with, a just appreciation of one's own defects.

Finally, by a remarkable piece of intellectuallegerdemain, Aquinas makes it not only compatible with, but a counterpart of, the great-souled man's alleged virtueof magnanimity.

Humility, he says, ensures that one's ambitions are based on a just assessment of one's defects,magnanimity that they are based on a just assessment of one's gifts.Aquinas is anxious to reconcile the virtue-based ethic of Aristotle with the role of divine law in the Christian moralsystem.

In Aristotle it is reason which sets the goal of action and sets the standard by which actions are to bejudged; according to the Bible, the standard is set by the law.

But there is no conflict, because law is a product ofreason.

Human legislators, the community or its delegates, use their reason to devise laws for the general good ofindividual states.

But the world as a whole is ruled by the reason of God.

The eternal plan of providentialgovernment, which exists in God as ruler of the universe, is a law in the true sense.

It is a natural law, inborn in allrational creatures in the form of a natural tendency to pursue the behaviour and goals appropriate to them.

Thenatural law is simply the sharing, by rational creatures, in the eternal law of God.

It obliges us to love God and ourneighbour, to accept the true faith, and to offer worship.Many times Aquinas returns to the passage in the final book of the Nicomachean Ethics which values thecontemplative life above the active life.

He treats it in several different ways, one of the most interesting of whichis his application of Aristotle's teaching to the topic of the vocations of various religious orders.

All religious orders,he says, are instituted for the sake of charity: but charity includes both love of God and love of neighbour.

Thecontemplative orders seek to spend time on God alone; the active orders seek to serve the needs of their fellows.Now which are to be preferred, contemplative or active orders? Aquinas draws a distinction between two kinds ofactive life.

There is one kind of active life which consists entirely in external actions, such as the giving of alms, orthe succour of wayfarers; but there is another kind of active life which consists in teaching and preaching.

In theseactivities the religious person is drawing on the fruits of previous contemplation, passing on to others the truthsthus grasped.

While the purely contemplative life is to be preferred to the purely active life, the best life of all forthe religious is the life which includes teaching and preaching.

‘Just as it is better to light up others than to shinealone, it is better to share the fruits of one's contemplation with others than to contemplate in solitude.' St Thomasdoes not specify what religious order he has in mind; but his phrase contemplata aliis tradere served as a motto forthe Dominican Order.Neither in his lifetime nor for long after his death was Aquinas regarded as a uniquely authoritative Catholic thinker.Three years after his death a number of propositions resembling positions he had held were condemned byecclesiastical authorities in Paris and Oxford, and it was half a century before he was generally regarded as theologically sound.

Even after his canonization in 1323 he did not enjoy, even within his own Order,the special prestige assigned to him by Catholics in recent times.

In the nineteenth century Pope Leo XIII, in anencyclical letter, gave him official status as the foremost theologian of the Church, and in the twentieth centuryPope Pius X gave a similar accolade to his philosophy.

This ecclesiastical endorsement harmed rather than helpedAquinas' reputation outside the Catholic Church, but at the present time his extraordinary gifts are gradually beingrediscovered by secular philosophers.. »