But this happens in different ways according to love of concupiscence, and love of friendship.  For in love of concupiscence he who desires something intensely, is moved against all that hinders his gaining or quietly enjoying the object of his love.  It is thus that husbands are said to be jealous of their wives, lest association with others prove a hindrance to their exclusive individual rights.  In like manner those who seek to excel, are moved against those who seem to excel, as though these were a hindrance to their excelling.  And this is the zeal of envy, of which it is written (Ps. 36:1):  “Be not emulous of evil doers, nor envy (zelaveris) them that work iniquity.”

On the other hand, love of friendship seeks the friend’s good:  wherefore, when it is intense, it causes a man to be moved against everything that opposes the friend’s good.  In this respect, a man is said to be zealous on behalf of his friend, when he makes a point of repelling whatever may be said or done against the friend’s good.  In this way, too, a man is said to be zealous on God’s behalf, when he endeavors, to the best of his means, to repel whatever is contrary to the honor or will of God; according to 3 Kings 19:14:  “With zeal I have been zealous for the Lord of hosts.”  Again on the words of John 2:17:  “The zeal of Thy house hath eaten me up,” a gloss says that “a man is eaten up with a good zeal, who strives to remedy whatever evil he perceives; and if he cannot, bears with it and laments it.”

Reply Obj. 1:  The Apostle is speaking in this passage of the zeal of envy; which is indeed the cause of contention, not against the object of love, but for it, and against that which is opposed to it.

Reply Obj. 2:  Good is loved inasmuch as it can be communicated to the lover.  Consequently whatever hinders the perfection of this communication, becomes hateful.  Thus zeal arises from love of good.  But through defect of goodness, it happens that certain small goods cannot, in their entirety, be possessed by many at the same time:  and from the love of such things arises the zeal of envy.  But it does not arise, properly speaking, in the case of those things which, in their entirety, can be possessed by many:  for no one envies another the knowledge of truth, which can be known entirely by many; except perhaps one may envy another his superiority in the knowledge of it.

Reply Obj. 3:  The very fact that a man hates whatever is opposed to the object of his love, is the effect of love.  Hence zeal is set down as an effect of love rather than of hatred. ________________________

FIFTH ARTICLE [I-II, Q. 28, Art. 5]

Whether Love Is a Passion That Wounds the Lover?

Objection 1:  It would seem that love wounds the lover.  For languor denotes a hurt in the one that languishes.  But love causes languor:  for it is written (Cant 2:5):  “Stay me up with flowers, compass me about with apples; because I languish with love.”  Therefore love is a wounding passion.