“There are five stages in the growth of love: first is to think someone pleasant, that is, someone thinks of someone else as being nice or is charmed by their character. This is part of making friends. Then there is admiration; that is the desire to be near the person that one admires. Then there is close friendship when you miss the other one terribly when they are absent. Then there is amorous affection when you are completely obsessed with the loved one. In the special vocabulary of love this is called ‘ishq, “the slavery of love”. Finally, there is passion, when one can no longer sleep, eat or think. This can make you ill to the point of delirium or even death. Beyond this, there is absolutely no place where love ends.”
Ibn Ḥazm, Morals and Right Conduct in the Healing of Souls.