I answer that, As stated above (II-II:123:1), the moral virtues are directed to the good, inasmuch as they safeguard the good of reason against the impulse of the passions. Now among the passions sorrow is strong to hinder the good of reason, according to 2 Corinthians 7:10, “The sorrow of the world worketh death,” and Sirach 30:25, “Sadness hath killed many, and there is no profit in it.” Hence the necessity for a virtue to safeguard the good of reason against sorrow, lest reason give way to sorrow: and this patience does. Wherefore Augustine says (De Patientia ii): “A man’s patience it is whereby he bears evil with an equal mind,” i.e. without being disturbed by sorrow, “lest he abandon with an unequal mind the goods whereby he may advance to better things.” It is therefore evident that patience is a virtue.
This brings to mind things like a martyr being afflicted by others for the truth that he holds and enduring this steadfastly, but in fact it applies well even to the ordinary idea of patience, according to which, for example, we might say that Ray Kurzweil’s impatience for technological progress leads him to false opinions about current historical trends.
We can illustrate this with a little story. Peter, impatient to get home from work, exceeds the speed limit and weaves in and out of traffic. Minutes before getting home, he hits a slippery patch on the road. His car goes off the road, ramming a tree and killing him.
Despite being nothing but a story, it is one that has without a doubt been played out in real life with minor or major variations again and again. We can apply the saying of St. Augustine quoted by St. Thomas. Peter’s patience would consist in “bearing evil with an equal mind,” that is, enduring the fact that he is not home yet without disturbance, “lest he abandon with an unequal mind the goods whereby he may advance to better things,” that is, since his disturbed and unequal mind leads him to abandon the goods, that is, the ordered manner of driving, whereby he may advance to better things, that is, actually to get home.
Patience is rightly thought to be related to the virtue of humility. One who judges rightly about his place in the order of things will understand that it is natural in this order that what is best tends to come last. The good wine is served last. Thus such a person should endure without disturbance the lack that comes earlier, in order not to abandon the good by which he might achieve the good that comes later.