For Plato, love is an intermediate state between possession and deprivation. For Alain Badiou, love is "the procedure that makes truth out of the disjunction of sexuated positions." (Infinite Thought, p. 163) 

Freud stressed the risks of love as a means to happiness. "We are never so defenceless against suffering as when we love, never so helplessly unhappy as when we have lost our loved object or its love." (Civilization and its Discontents, p.29) For Freud, "There is good reasons why a child sucking at his mother's breast has become the prototype for every relation of love. The finding of an object is in fact a re-finding of it." ("Three Essays on Sexuality) Jean Laplanche points out that a displacement has taken place nonetheless. "The lost object is the object of self-preservation, and the object one seeks to refind in sexuality is an object displaced." (Life and Death in Psychoanalysis, p. 20) 

He distinguishes between fully sensual genital love and "aim-inhibited" love or "affection" that describes the feelings within a family or leads to "friendships." (Civilization and its Discontents, p.49-50) (see sublimation) Unlike the erotogenic component of sexuality, affection is directed upon an object from the beginning, and difficulties arise when this object does not, indeed refuses to, coincide with the object of the rest of sexuality. Love (and hate) are "concepts that cannot be made use of for the relation of instincts to their objects, but are reserved for the relations of the total ego to objects." (XIV,137.)

see "ideal love" in transcendence / immanence the submission to a powerful other who seems to embody the agency and desire one lacks in oneself, someone who can be a mirror of one's ideal image of the self. Plato had to hold philosophical love, philo-sophia at a distance from real love, gripped in the malaise of a desire for an object. 

"It was once said that falling in love is the act of overvaluing the marginal differences which exist between one woman and another (or one man and another). But this can also be said about works of art or horses." Carlo Ginzburg, "Clues" p. 124. -- and don't some people fall in love with works of art or horses as well? "The lover desires the as only insofar as it is such -- this is the lover's particular fetishism." (Giorgio Agamben) see quodlibet