Philosophers on Love

What is love? Is it desirable? It is the same thing as happiness, or perhaps the opposite?

Schopenhauer was perhaps the first mainstream philosopher to write primarily about love, both as a moral emotion and generally how two people fall for each other. Schopenhauer said that contrary to popular belief, love was the opposite of happiness - love being caused by a biological need to reproduce.

Then, in the German tradition, Nietzsche came onto the scene. Raised in Schopenhauer's views, Nietzsche offered a different approach to love - it is the opposite not of happiness, but of friendship (perhaps they are the same thing, as according to Aristotle the ancient). According to Nietzsche, the only love that one should have is for thyself (differing from Kant who believed self-love good but also to "love" - although actually perhaps not so different because Kant was strictly against pathological love) so perhaps the Germans were idealists in this sense.

But in the German literature you see the perils of love and the epic fails of all of the characters who do fall in love.

Derrida describes love as lack (which Aristotle would say equals desire and arguably all philosophers). You love a woman because you desire what you lack (and now perhaps same-sex is supported by this theory). And friendship, you see yourself in the other and strive to be good like them. 

Because love is in another world and everyone's experience is unique please share!