Pain itself can be pleasurable accidentally in so far as it is accompanied by wonder, as in stage-plays; or in so far as it recalls a beloved object to one's memory, and makes one feel one's love for the thing, whose absence gives us pain. Consequently, since love is pleasant, both pain and whatever else results from love, in so far as they remind us of our love, are pleasant.
Thomas AquinasOne day when Thomas Aquinas was preaching to the local populace on the love of God, he saw an old woman listening attentively to his every word. And inspired by her eagerness to learn more about her God whom she loved so dearly, he said to the people: It is better to be this unlearned woman, loving God with all her heart, than the most learned theologian lacking love.
Thomas AquinasArrive at knowledge over small streamlets, and do not plunge immediately into the ocean, since progress must go from the easier to the more difficult.
Thomas AquinasGiven the sin of impiety through which they [the Romans] sinned against the divine nature [by idolatry], the punishment that led them to sin against their own nature followed.... I say, therefore, that since they changed into lies [by idolatry] the truth about God, He brought them to ignominious passions, that is, to sins against nature; not that God led them to evil, but only that he abandoned them to evil.
Thomas Aquinas