Thomas Aquinas

“ For this reason justice and its parts are properly about operations as their proper matter. On the other hand, in some operations, good and evil depend only on commensuration with the agent. Consequently good and evil in these operations depend on the way in which man is affected to them. And for this reason in such like operations virtue must needs be chiefly about internal emotions which are called the passions of the soul, as is evidently the case with temperance, fortitude and the like. ”

“ For the first considers operations as the effect of virtue, while the other two consider operation and passion as concurring in the same effect. But in some cases virtue is chiefly about operations, in others, about passions, for the reason given above. ”

“ Again, the species of the object of appetite, as of any thing, depends on its specific form which it receives from the agent. But we must observe that the matter of the passive subject bears a twofold relation to the agent. For sometimes it receives the form of the agent, in the same kind specifically as the agent has that form, as happens with all univocal agents, so that if the agent be one specifically, the matter must of necessity receive a form specifically one: thus the univocal effect of fire is of necessity something in the species of fire. ”

“ Accordingly, if we take a good, and it be something discerned by the sense of touch, and something pertaining to the upkeep of human life either in the individual or in the species, such as the pleasures of the table or of sexual intercourse, it will belong to the virtue of "temperance." ”

“ Consequently man's good which is the object of love, desire and pleasure, may be taken as referred either to a bodily sense, or to the inner apprehension of the mind: and this same good may be directed to man's good in himself, either in his body or in his soul, or to man's good in relation to other men. ”

“ Further, the passions are acts or movements of the sensitive appetite. Now it needs a greater difference to differentiate habits than acts. Hence diverse objects which do not diversify the species of passions, do not diversify the species of moral virtue: so that there is but one moral virtue about all objects of pleasure, and the same applies to the other passions. ”

“ But the thing due is not of the same kind in all these virtues: for something is due to an equal in one way, to a superior, in another way, to an inferior, in yet another; and the nature of a debt differs according as it arises from a contract, a promise, or a favor already conferred. ”

“ That justice which seeks the common good is another virtue from that which is directed to the private good of an individual: wherefore common right differs from private right; and Tully (De Inv. ii) reckons as a special virtue, piety which directs man to the good of his country. But that justice which directs man to the common good is a general virtue through its act of command: since it directs all the acts of the virtues to its own end, viz. ”

“ In operations of this kind there needs to be some power to regulate the operations in themselves: such are buying and selling, and all such operations in which there is an element of something due or undue to another. ”