The Mystery of Love: Arthur Schopenhauer
German philosopher Arthur Schopenhauer was born in Gdańsk, Poland in 1788 and died in Frankfurt in 1860. He was Nietzsche's greatest inspiration, but he's most famous for his essay "Metaphysics of Love."
In it, he wrote this about men who fall in love: "First of all let them take into consideration that the creature whom they are idealizing to-day in madrigals and sonnets would have been ignored almost entirely by them if she had been born eighteen years previously. Every kind of love, however ethereal it may seem to be, springs entirely from the instinct of sex; indeed, it is absolutely this instinct, only in a more definite, specialized, and perhaps, strictly speaking, more individualized form."
According to Schopenhauer, sexual attraction can be explained by nature being concerned with keeping physical features within certain boundaries. If, for example, a man has a rather big nose, he might be attracted to a woman with a small nose, so that any offspring a possible relationship might yield, has the right nose to be called human.
This view explains how love at first sight works, and why a man or woman can be attracted to a person, that might not be pretty at all to someone else. Of course there is a category of people who are simply beautiful by any standard, but those are the lucky few.
But if that's true, then why do we have the impression that many couples resemble each other so much? Probably because Schopenhauer, who wasn't known for being very passionate himself, was mainly looking at physical attraction, or the element of passion. In modern psychology, apart from passion being essential to a relationship, two other elements are distinguished as well, which are "proximity" and "similarity." When those three elements come together, psychologists say, a relationship is almost inevitable.
Studies have shown that even today, in the age of internet, people living, studying or working close to each other are far more likely to enter in a relationship than people farther away from each other. This seems obvious but it's one of the few aspects of love that science has been able to determine.
The third element, similarity, is about culture and having more or less the same ideas and views. People with totally different backgrounds are less likely to enter in a long-term relationship. When it comes to their proffessions, teachers for instance are far more likely to have a teacher as their partner than would be expected by pure chance.
The problem here, at least from a biological perspective, is the danger of inbreeding. Research has shown that nature somehow prevents brothers and sisters from falling in love with each other, even when they were not raised in the same family. But marriages between cousins are not uncommon. In some Arab countries today, between 40% and 50% of all marriages are consanguineous or between close family members.
At the same time, it's remarkable how people in a long-term relationship can increasingly resemble each other. Close relationships may even spark an entirely different way of thinking and acting, almost like a "shared mind." Partners develop their own language and insider-jokes that nobody understands, and they even start to look and sound alike.
Human behavior is the result of the interaction between genes and their environment in the broadest sense, perhaps supplemented by a small amount of coincidence. Or boredom, as Schopenhauer might have called it. In order to explain our personal preferences, we would need to know everything about both our genetic makeup and our experiences during (and even before) our lives. Obviously, that is not possible.
A more spiritual view of love as an all-pervasive force, roughly equivalent to God, is presented by the character Dr. Amelia Brand in the 2014 movie "Interstellar":
"Love isn’t something we invented. It’s observable, powerful, it has to mean something… Love is the one thing we’re capable of perceiving that transcends dimensions of time and space."
Love is a mystery, and it might be best to leave it at that and just be grateful for it's existence. As Plato famously said it around 400 BC: "At the touch of love, everyone becomes a poet."