Harry Potter and the Half-Blood Prince
How we cite our quotes:
"By an act of evil – the supreme act of evil. By committing murder. Killing rips the soul apart. The wizard intent upon creating a Horcrux would use the damage to his advantage. He would encase the torn portion – " (23.62)
If you rip a soul apart, wouldn't you damage it? Doesn't ripping a soul apart sound like a violent way to treat your soul? If Voldemort's soul is divided seven times, we can't imagine that any one piece is very healthy or happy. How can it be powerful, then, if it is a weak fraction of a soul?
"Well, Harry," said Dumbledore, "I am sure you understood the significance of what we just heard. At the same age as you are now, give or take a few months, Tom Riddle was doing all he could to find out how to make himself immortal." (23.78)
Why does immortality appeal to Tom Riddle and not to Harry Potter?
"'Further than anybody.' And I thought I knew what that meant, though the Death Eaters did not. He was referring to his Horcruxes, Horcruxes in the plural, Harry, which I do not believe any other wizard has ever had. Yet, it fitted: Lord Voldemort has seemed to grow less human with the passing years, and the transformation he has undergone seemed to me to be only explicable if his soul was mutilated beyond the realms of what we might call 'usual evil'…" (23.92)
So, if Voldemort has gone "beyond the realms of what we might call 'usual evil,' where has he gone? There's a competitive streak in Voldemort, a desire to be better, stronger, and more creative than any other wizard. It would seem he found the most difficult task a wizard could ever assume, and he proved that he could master this task. He is a talented wizard who is in search, constantly in search.