Horcruxes are introduced in the sixth Harry Potter novel, Harry Potter and the Half-Blood Prince. On page 497, we learn that a horcrux is "an object in which a person has concealed part of their soul." Further, also on page 497, we learn that "you split your soul . . . and hide part of it in an object outside the body" and that, after doing so, "even if one's body is attacked or destroyed, one cannot die, for part of the soul remains earthbound and undamaged." Then, on page 498, we learn that splitting the soul is done by committing murder, for "[k]illing rips the soul apart."
This information about horcruxes is conveyed as Harry Potter and Professor Albus Dumbledore observe a memory of Professor Horace Slughorn, using Dumbledore's pensieve. In this memory, Professor Slughorn is talking privately with a Hogwarts student, Tom Riddle, who later becomes the evil Lord Voldemort. In the memory, Tom wants to know about horcruxes, one of the most evil forms of dark magic, and Professor Slughorn reluctantly answers his questions.
In Harry Potter and the Half-Blood Prince, Lord Voldemort, a.k.a. Tom Riddle, has pushed the boundaries of dark magic further than any other dark wizard. Using horcruxes, he has split his soul, not just in two, but into seven pieces, seven being a powerful magical number. This, Voldemort believes, will insure his immortality. One horcrux can possibly be found and destroyed, but with so many horcruxes, the likelihood that they will all be found and destroyed is so slim as to be negligeable. And the power of the magical number seven gives extra protection to the pieces of Voldemort's soul. As long as any piece of his soul is encased in a horcrux, Voldemort cannot really die, although he can be reduced to a very diminished form of existence. But, from this diminished existence, Voldemort can rebuild himself.
To destroy Voldemort and the evil he plans to unleash upon the world, it is necessary to destroy each of the horcruxes and then to kill Voldemort himself. Dumbledore believes that the seven pieces of Voldemort's soul have been split as follows:
- Within Tom Riddle's diary (already destroyed in Harry Potter and the Chamber of Secrets)
- Within Slytherin's ring (already destroyed by Dumbledore earlier in Harry Potter and the Half-Blood Prince)
- Within Slytherin's locket (believed to be destroyed by someone with the initials R.A.B., as discovered by Harry toward the end of Harry Potter and the Half-Blood Prince)
- Within Hufflepuff's cup
- Within some other object belonging to Ravenclaw or Gryffindor
- Within Voldemort's snake, Nagini
- Within Voldemort himself (the final piece)
So, we have this evil and powerful wizard, Voldemort, who, as stated on page 500 of Harry Potter and the Half-Blood Prince, is an individual "so determined to evade death that he would be prepared to murder many times, rip his soul repeatedly, so as to store it in many, separately concealed Horcruxes." As we learn on page 498, this is horribly unnatural, for "the soul is supposed to remain intact and whole. Splitting it is an act of violation, it is against nature."
Voldemort is an individual with a single-minded focus--one might say a deep obsession--on becoming immortal and gaining as much power as possible, even pushing the boundaries beyond what has been thought possible. Needless to say, the type of power that Voldemort craves is power over others. So deep is Voldemort's desire for immortality and power that he is completely willing to rip his soul apart, not just in two, but into seven pieces--committing murder each time.
The world is filled with people who, in large and small ways, focus on obtaining something so intensely that what is truly important in life gets swept aside. Certainly, we see this in male politicians who find it so important to gratify their momentary sexual desires that they have sex with a prostitute or an intern or a woman other than their wife, completely tossing aside their marriage commitment, their family's happiness, the respect of their community, and their political career. This is perhaps different from Voldemort in that Voldemort is constantly obsessed with immortality and power, whereas these politicians appear to give in to gratification in the moment. But the willingness to toss aside deeper values for selfish reasons is the same. In both cases, the individual destroys himself in order to have something lesser--Voldemort destroys his soul to have earthly immortality, and the politician destroys the trust of his wife, his family, and his community to have illicit sex.
I would say that a person rips their soul, or at least harms their soul in some way, through acts of various degrees of seriousness. These include murder, rape, verbal abuse, illicit sex, stealing, gossiping, lying, power plays, and unkind words. Thoughts count, too. In fact, so does any thought, word, or deed that violates the Golden Rule. Anytime, we treat others in ways that we would not want to be treated ourselves, we harm our souls. This includes thinking unkindly about others or talking unkindly about others when they are not present. It includes acting unkindly toward others, whether directly or indirectly. (An indirect act of unkindness, for example, might be leaving a mess behind for someone else to clean up. This can happen on an individual level as well as on a collective level. We might, for instance, consider the collective behavior of leaving a polluted world to future generations or leaving future generations burdened with a heavy financial debt.) Unkindness can often be subtle, as when we subtly put someone "in their place" by talking down to them.
Whenever a person engages in unkind behavior, it is because that person strongly desires something lesser than the joy of a principled life, such as power, money, revenge, sex. I will also say that a person can harm their soul through unfaithful behavior, even unfaithfulness to self. This can happen when one is not faithful in caring for one's health, such as when one engages in smoking, substance abuse, overeating, or being a constant couch potato. In these cases, such things as a large or small high feeling, escape from reality, comforting tastes, or the pull of inertia become more important than assuming responsibility for maintaining one's health.
I should mention, though, that sometimes a person is in dire need of something that will save their life and may violate someone else's right in order to fulfill their own need. The author and feminist scholar of pornography, Andrea Dworkin, recounts how she was once in an abusive relationship in which she was kept isolated from others and never allowed to have money of her own so that she remained completely dependent on her "lover" and had no means of escape. She finally did manage to escape, but to do so she found it necessary to steal money. I hardly know what to say about this, but I do find it understandable.
In any case, the horcruxes in Harry Potter and the Half-Blood Prince point out the very real danger of harming one's soul in large ways by murder or rape but, if we think about it, also in daily actions, words, or thoughts of unkindness or unfaithfulness.