It is requisite for the relaxation of the mind that we make use, from time to time, of playful deeds and jokes.
Thomas AquinasIf a thing can be done adequately by means of one, it is superfluous to do it by means of several; for we observe that nature does not employ two instruments [if] one suffices.
Thomas AquinasIt is not theft, properly speaking, to take secretly and use another's property in a case of extreme need: because that which he takes for the support of his life becomes his own property by reason of that need
Thomas AquinasIf there were some solitary or feral man, the passions of the soul would be sufficient for him; by them he would be conformed to things in order that he might have knowledge of them. But because man is naturally political and social, there is need for one man to make his conceptions known to others, which is done with speech. So significant speech was needed if men were to live together. Which is why those of different tongues do not easily live together.
Thomas AquinasSecondly, man sins against nature when he goes against his generic nature, that is to say, his animal nature. Now, it is evident that, in accord with natural order, the union of the sexes among animals is ordered towards conception. From this it follows that every sexual intercourse that cannot lead to conception is opposed to man's animal nature.
Thomas Aquinas