It would seem that the ingratitude, whereby a subsequent sin causes the return of sins previously forgiven, is a special sin. For, the giving of thanks belongs to counter passion, which is a necessary condition of justice. But justice is a special virtue. Therefore this ingratitude is a special sin. Thanksgiving is a special virtue. But ingratitude is opposed to thanksgiving. Therefore ingratitude is a special sin.
Thomas AquinasThe soul, which is the first principle of life, is not a body, but the act of a body; just as heat, which is the principle of calefaction, is not a body, but an act of a body.
Thomas AquinasIt is requisite for the relaxation of the mind that we make use, from time to time, of playful deeds and jokes.
Thomas AquinasWonder [admiratio astonishment, marvel] is a kind of desire for knowledge. The situation arises when one sees an effect and does not know its cause, or when the cause of the particular effect is one that exceeds his power of understanding. Hence, wonder is a cause of pleasure insofar as there is annexed the hope of attaining understanding of that which one wants to know. ... For desire is especially aroused by the awareness of ignorance, and consequently a man takes the greatest pleasure in those things which he discovers for himself or learns from the ground up.
Thomas Aquinas