Secondly, 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 AquinasWe are like children, who stand in need of masters to enlighten us and direct us; God has provided for this, by appointing his angels to be our teachers and guides.
Thomas AquinasThat the saints may enjoy their beatitude and the grace of God more abundantly they are permitted to see the punishment of the damned in hell.
Thomas Aquinas