I'll repost the definition I concur with, from this thread:
http://forums.somd.com/showthread.php?s=&threadid=12893
Love, we are repeatedly taught, consists of self-sacrifice. Love based on self-interest, we are admonished, is cheap and sordid. True love, we are told, is altruistic. But is it?
Imagine a Valentine's Day card which takes this premise seriously. Imagine receiving a card with the following message: "I get no pleasure from your existence. I obtain no personal enjoyment from the way you look, dress, move, act or think. Our relationship profits me not. You satisfy no sexual, emotional or intellectual needs of mine. You're a charity case, and I'm with you only out of pity. Love, XXX."
Needless to say, you would be indignant to learn that you are being "loved," not for anything positive you offer your lover, but—like any recipient of alms—for what you lack. Yet that is the perverse view of love entailed in the belief that it is self-sacrificial.
Genuine love is the exact opposite. It is the most selfish experience possible, in the true sense of the term: it benefits your life in a way that involves no sacrifice of others to yourself or of yourself to others.
To love a person is selfish because it means that you value that particular person, that he or she makes your life better, that he or she is an intense source of joy—to you. A "disinterested" love is a contradiction in terms. One cannot be neutral to that which one values. The time, effort and money you spend on behalf of someone you love are not sacrifices, but actions taken because his or her happiness is crucially important to your own. Such actions would constitute sacrifices only if they were done for a stranger—or for an enemy. Those who argue that love demands self-denial must hold the bizarre belief that it makes no personal difference whether your loved one is healthy or sick, feels pleasure or pain, is alive or dead.
It is regularly asserted that love should be unconditional, and that we should "love everyone as a brother." We see this view advocated by the "non-judgmental" grade-school teacher who tells his class that whoever brings a Valentine's Day card for one student must bring cards for everyone. We see it in the appalling dictum of "Hate the sin, but love the sinner"—which would have us condemn death camps but send Hitler a box of Godiva chocolates. Most people would agree that having sex with a person one despises is debased. Yet somehow, when the same underlying idea is applied to love, people consider it noble.
Love is far too precious to be offered indiscriminately. It is above all in the area of love that egalitarianism ought to be repudiated. Love represents an exalted exchange—a spiritual exchange—between two people, for the purpose of mutual benefit.
You love someone because he or she is a value—a selfish value to you, as determined by your standards—just as you are a value to him or her.
It is the view that you ought to be given love unconditionally—the view that you do not deserve it any more than some random bum, the view that it is not a response to anything particular in you, the view that it is causeless—which exemplifies the most ignoble conception of this sublime experience.
The nature of love places certain demands on those who wish to enjoy it. You must regard yourself as worthy of being loved. Those who expect to be loved, not because they offer some positive value, but because they don't—i.e., those who demand love as altruistic duty—are parasites. Someone who says "Love me just because I need it" seeks an unearned spiritual value—in the same way that a thief seeks unearned wealth. To quote a famous line from The Fountainhead: "To say 'I love you,' one must know first how to say the 'I.'"
by Gary Hull, Ph.D. in philosophy, a senior writer for the Ayn Rand Institute in Marina del Rey, Calif.