The modern mind conceives of the self as imminent. This is the key, I'm beginning to believe, to understanding the modern mindset.
Descartes famously started off his proof with I think therefore I am. He went on to discuss what that means, but because he was looking for a self-evident premise, he took the concept of the self to have the barest possible meaning. And though the blame can't all be laid on him, yet in doing so he plunged the world into a darkness which it has yet to recover from.
For the barest possible definition of the self is simply a collection of memories. People manage somehow to deny the self-evidently true existence of free will, but no one — not even the most committed Buddhist or the most insane materialist — has as yet tried to deny the existence of memory. The self has memory, but defining the self as memory is very dangerous indeed. Descartes was able to do it safely so far as his personal sanity was concerned because he was a mathematician, and mathematicians are used to abstracting things and remembering that the abstraction is not the whole. Alas for the world, Descartes was not careful who he talked to.
This theme was developed more fully by others, after Descartes tried and failed to provide a mathematical grounding for real knowledge. (Mathematics is knowledge of what might be, if the premises are granted, but never what actually is.) What Descartes took as a convenient definition, others took as a complete definition. The self stopped being an actual substance, and became merely a collection, and depending how reductionist the philosopher, perhaps also a velocity (that is, a particular tendency toward what new memories get added).
Any amputation of part of the soul will naturally be disastrous, but this was a lopping off of most of the soul. It is perhaps odd that it was so barely noticed; the soothing effect of a voluminous flow of long words with uncommon definitions may have something to do with it initially. Gone from the soul is form, will, intellect, and even substance. It should hardly be surprising that the cultural ideal of man which followed is an unthinking hedonist with a pleasing face and convenient impulses.
But even those who amputate their intellect still think, they just think badly. So the self the modern mind has to think about is a purely imminent self — a collection of experiences. A man's worth is, therefore, the sum of the worth of his experiences. (This, incidentally, is why dying men wish that they had seen something which their working for accomplishments prevented; the accomplishments are not part of him, while the work is.) But here there is a great problem for the modern mind. What are a man's experiences worth?
There have been a few people mad and desperate enough to try to claim that man can be the ground of his own worth, but it's just too blisteringly obvious that man is a contingent being for anyone to maintain this without impressive quantities of drugs taken without intermission. A functioning human brain just can't take the idea seriously, however impressive its ability to lie to itself. Death and taxes are the two great certainties in life, to use a common proverb, and both disprove the self-existence of a man.
A man cannot be a premise. God can be a premise, but to the modern mind God is dead. Without premises, you can't have a valid argument, but you can have something which looks like a valid argument. Circular arguments are not valid, but they do have many of the qualities of valid arguments. In particular, there's more than one step, which is not self-evidently false, and each statement in the argument does at least follow from the one before it.
So from where does the worth of a man's life come from? From another man. In the ancient world this took the form of glory, where you just had enough men, continuing on into the future that you didn't have to notice that it's a circular argument. One might call this argument by exhaustion. If you have enough steps in your argument, not one can follow it, and so it can't be pronounced invalid. It was also done in the ancient world by friendship, which is similar to how it's done in the modern world, except that it was less pronounced (typically) in the ancient world because the ancient world was pagan, which one can loosely define as the suspicion that something worthwhile is true.
In the modern world, science has killed the hope that there's something outside of the world of men, so friendship is more pronounced. By a strange irony, though, friendship has through its conquering lost its name, and turned into the concept of a soul-mate. This needs a little explanation, I think.
C.S. Lewis in his book The Four Loves described the difference between friends and lovers in that friends look together at the world, lovers at each other. If the classic position of friends is shoulder-to-shoulder, the classic position of lovers is face-to-face. Well and good while there's a world to look at, but how if there's no world for the friends to look at together? During the death of the intellect which strangely bears the name The Enlightenment, the world shrank and eventually all but disappeared. With the inability to criticize came the inability to praise, and so all that was left was talking about oneself ("this painting makes me feel..."). Nothing is knowable except what reveals itself, and to the modern mind nothing reveals itself except verbally. (There is a special exception where sharing the same experience makes another knowable in that aspect since that aspect of the other is identical with that aspect of oneself, and so the other can be known through the self, since in that aspect the two are one.) In the modern world, the only position available to friends is face-to-face.
So friends become lovers and lovers friends and everyone must find his soul mate. For it is the soul mate who gives one's self validity. The soul mate knows one's self (that is, has heard all of your stories), and values one's self, and so gives it value. But in this vale of tears doubt springs eternal, or more charitably, contingent beings need continual nourishment. How is the soul mate to know the relationship still exists?
From this dilemma springs the modern conception of sex. Sex is no longer the participation with God in the act of creation: God is dead and anyway, a child doesn't exist until it has experiences, so sex can't in any sense create it. But sex is something which people are not generally willing to do with each other, so it can serve as an outward sign of the value that each partner feels for, and therefore imparts to, the other. That is, it becomes a sacrament of the relationship.
Sacraments have an air of arbitrariness about them. Certainly, it's not obvious that Christ could not have chosen to make rice and not wheat the sacrament of his body. It's not obvious that God could not have chosen to use oil for baptism and water for confirmation. Doubtless God has good reasons for the choices he made, but they have about them the air of choice.
And so when two soul mates make a sacrament to nourish their union, there is an air of arbitrariness in its form. Here, of course, the goodness of the reasons admits of doubt, but in a real sense anything will do so long as its fixed. The traditional choice is of course a penis in a vagina, but for this purpose there's no reason that a penis in a mouth or an anus won't do. A finger in a vagina has all the same qualifications. And at the end of the day, so long as a man isn't willing to let anyone but his soul mate do it, and is willing to let his soul mate do it, anything will really do. A finger in an ear, drinking from the same milk shake, anything with a general reluctance and individual acceptance will do. And in fact a general reluctance which is specifically overcome can be a stronger sign and more nourishing sacrament than something one's soul mate is inclined to. If they value you so much that they're willing to let you do something painful or disgusting to them, the value they set on you must be high indeed. Hence perversion. (The reverse logic also holds — if you're willing to let someone do something painful or disgusting to you, it shows how much you love them, and so they will have to love you back.)
This is why celibacy is so hated in the modern world. Marriage (another sacrament of the soul-mate) means life. Being alone is, effectively, death. This also explains the importance of divorce; if a soul-mate relationship has disintegrated, it is imperative that the bonds which prevent a new soul-mate from being found be immediately dissolved. Marriage is not a suicide pact.
This is why there's such an emotional attachment on the part of straight people to gay marriage, and why the opponents of gay marriage are called haters — opposing gay marriage is tantamount to wanting to execute gays. This is also why a man who is sexually attracted to other men but resists this impulse is called self-loathing: he's committing suicide.
This also generates an unending river of advice columns on the subject of the tension between having a soul mate and the experiences that being with that soul mate generate not being ones that you want. In some cases, such as physical abuse, the answer is invariable to leave and find another soul mate, since no matter how much someone values you, there's also the question of the person who you're becoming. In twenty years it won't matter that you once loved hiking (since memory fades) if all you've done for those twenty years is get beaten and try to hide. No one wants to be a victim, and that's not a characteristic, but actually an identity. If you remain a victim for long enough, that's all that you are. There is no you apart from the victim.
There's also the concept of being subsumed into another; this problem requires one to consider one's velocity as part of oneself. That is, part of oneself is the sort of new experiences that you seek out and add to yourself. If your interests become dominated by those of your soul mate so that the new experiences you add to yourself are the sort that he would add to himself, and not the sort that you would otherwise have added to yourself, you are literally becoming him. Your memories are becoming the same, and your velocity is becoming the same. You will in time no longer be distinguishable. But this is why there's the unending flow of advice not to allow yourself to be subsumed in your lover, why its important to have space and a soul mate who respects your need for space. Maintaining a constant flow of unique experiences is the only way to stay alive.
There are many other insanities of modern life that the imminent self explains, as well. For example, it's one reason why travel is so popular (there are other, more legitimate reasons). Visiting Paris makes Paris part of you. People love Paris, and so by identity they love you, too. Italy is great, and by acquiring memories of Italy, it becomes part of you, and so you become great.
I suspect that this also gives a partial explanation of the wedding-industrial complex. Cultures throughout the globe and throughout history have loved to throw extravagant parties, so the thing needs no uniquely modern explanation. Big parties are fun. Yet the imminent self does help to feed this industry, and especially to the concept of the bridezilla. One's wedding day becomes a part of one, and since big parties are quite rare, one will have few of them in one's self. Hence the importance of everything going exactly how the bridezilla wants it — in controlling what happens on her wedding day, she's crafting herself. The self she will be for the rest of time is at stake. Indeed, the worst thing that she can have is a sense of perspective; seeing how much is at stake means that she needs to get unconditional surrender.
There is, incidentally, a curious question that the imminent self raises about concepts such as forgiveness and repentance. In particular, is repentance even possible with an imminent self? In one sense, the answer is clearly no, since repentance is really a form of suicide. Repudiating the past, to the degree that one believes it possible, means destroying a part of the self. Sin is privation of form, but no action no matter how vile can do ought but add to one's form with the imminent self. Guilt — the desire to repudiate parts of the past — then becomes the true privation of form, or at least the one real temptation, with repentance being the sin. One certainly sees this theory, but human beings have only very limited skill at acting according to obviously wrong theories (which is, by the way, one of the better proofs for the existence of God).