Thomas Aquinas Quotations

Thomas Aquinas / 1225–1274 / Latium, Kingdom of Italy / Theologian, Philosopher

Note: All quotations are taken from Summa Theologiae [Summary of Theology], written between 1265 and 1274.


It is natural to a man to love his own work (thus it is to be observed that poets love their own poems); and the reason is that we love to be and to live, and these are made manifest especially in our action.

Part II-II, Q. 26.


The virtue of chastity most of all makes man apt for contemplation, since sexual pleasures most of all weigh the mind down to sensible objects.

Part II-II, Q. 180.


Now among all passions inflicted from without, death holds the first place, just as sexual concupiscences are chief among internal passions. Consequently, when a man conquers death and things directed to death, his is a most perfect victory.

Part III, Supplement, Q. 96.


When our friends fall into sin, we ought not to deny them the benefits of friendship so long as there is hope of their mending their ways, and we ought to help them more readily to regain virtue than to recover money, had they lost it, since vir- tue is more akin than money to friendship. When, however, they fall into very great wickedness, and become incurable, we ought no longer to show them friendliness.

Part II-II, Q. 25.

Because the friendship of comrades originates through their own choice, love of this kind takes precedence of the love of kindred in matters where we arc free to do as we choose, for instance in matters of action. Yet the friendship of kindred is more stable, since it is more natural, and preponderates over others in matters touching nature. Consequently we are more bound to them in the providing of necessities.

Part II-II, Q. 26.

Good and Bad

The good is what should be done and pursued, and the bad is what should be avoided.

Part I-II, Q. 94.


Therefore man ought, out of charity, to love God, Who is the common good of all. more than himself, since happiness is in God as in the universal and fountain-head principle of all who are able to have a share of that happiness.

Part II-II, Q. 26.


Honour is not that reward of virtue, for which the virtuous work, but they receive honour from men by way of reward, as from those who have nothing greater to offer. But virtue’s true reward is happiness itself, for which the virtuous work, whereas if they worked for honour, it would no longer be virtue, but ambition.

Part I-II, Q. 2.

Human Nature

Man’s nature may be looked at in two ways: first, in its integrity, as it was in our first parent before
sin; secondly, as it is corrupted in us after the sin of our first parent. . . . man by his natural endowments could will and do the good proportionate to his nature, such as the good of acquired virtue, but not surpassing good, as the good of infused virtue. But in the state of corrupt nature, man falls short even of what he could do by his nature, so that he is unable to fulfil it by his own natural powers. Yet because human nature is not altogether corrupted by sin, so as to be shorn of every natural good, even in the state of corrupted nature it can, by virtue of its natural endowments, work some particular good, as to build dwellings, plant vineyards, and the like; yet it cannot do all the good natural to it, so as to fall short in nothing, just as a sick man can of himself make some movements, yet he cannot be perfectly moved with the movements of one in health, unless by the help of medicine he be cured.

Part I-II, Q. 109.


Charity signifies not only the love of God but also a certain friendship with Him; and this implies, besides love, a certain mutual return of love, together with mutual communion . . . Therefore just as friendship with a person would be impossible if one disbelieved in, or despaired of, the possibility of his fellowship or familiar intercourse, so too, friendship with God, which is charity, is impossible without faith, so as to believe in this fellowship and intercourse with God, and to hope to attain to
this fellowship. Therefore charity is altogether impossible without faith and hope.

Part I-II, Q. 65.

Now it is evident that through every mortal sin which is contrary to God’s commandments, an obstacle is placed to the outpouring of charity, since from the very fact that a man chooses to prefer sin to God’s friendship, which requires that we should follow His will, it follows that the habit of charity is lost at once through one mortal sin.

Part II-II, Q. 24.


If however we compare union with union, it is evident that the union arising from natural origin is prior to, and more stable than, all others, because it is something affecting the very substance, while other unions are something added above and may cease altogether. Therefore the friendship of kindred is more stable, while other friendships may be stronger in respect of that which is proper to each of them.

Part II-II, Q. 26.


Youth is a cause of hope for three reasons. . . . youth has much of the future before it, and little of the past; and therefore since memory is of the past, and hope of the future, it has little to remember and lives very much in hope. Again, youths, on account of the heat of their nature, are full of spirit, so that their heart expands, and it is owing to the heart being expanded that one tends to that which is arduous; therefore youths are spirited and hopeful. Likewise they who have not suffered defeat, nor had experience of obstacles to their efforts, are prone to count a thing possible to them. Therefore youths, through inexperience of obstacles and of their own shortcomings, easily count a thing possible, and consequently are of good hope.

Part I-II, Q. 40.