Albus Dumbledore is the archetypical wise old man in the Harry Potter books. No matter what type of evil chaos or machivellian politics are happening at Hogwarts or the world of wizarding, Albus Dumbledore rises above it, through his amazing Wizarding skills, intelligence and good humor. Albus Dumbledore is the one person Harry can depend on above all others at Hogwarts.
As the Harry Potter books have progressed, and the writing style and subject matter have become more mature, we have seen characters becoming more multifaceted. "The world isn't divided into good people and death eaters", as it says in the 5th book. One of the revelations of the 5th book was that James Potter, Harry's father, despite his allegiance to the cause of good, had an arrogant and cruel streak. However, so far, Albus Dumbledore has remained pure of any suggestion of negative traits.
However, if the two remaining books of the Harry Potter series contine the exponential rise in moral and personal complexity that we have seen so far, there is a good chance that Dumbledore might reveal at least a slight negative side. I doubt that there will be a major betrayal, but there will probably be at least some suspicion cast upon his motives.
One of the most curious things about Dumbledore is that in the first book, Harry states "he knows just about everything that goes on here", and indeed Dumbledore's powers of logic, insight, and ability to read minds is shown repeatedly in the series. However, if he does have such strong magical powers, why did he not detect:
- The fact that Professor Quirell, a man he is constantly in close proximity to, is possesed by Voldemort?
- That the ghost of Voldemort is possessing Ginny Weasley, and that a Basilisk is the monster that is stoning people?
- That Peter Pettigrew, a dark magician is hiding inside of Hogwarts, and has been for years, in the form of a rat?
- That Alastor Moody (again, someone he is in constant close contact with) is being impersonated by the younger Bartemious Crouch?
Either Dumbledore is either not paying attention, or he is overlooking very hazardous events for his own reasons.
There could be a story external explanation, that J.K. Rowling simply did not see the contradiction between Dumbledore's powerful insight and the fact that so much skullduggery goes on around him. However, being that Rowling seems to have thought her story arc out well in advance, it seems that she would have considered the implications of the contrast between characterization and plot.
Dumbledore may be trying to remove himself from events to allow Harry Potter and friends a larger hand in developing their own skill and wisdom. I don't think it is likely that Dumbledore has been planning anything that is actually malicious or evil, but I do believe that there may be some suspense in this regard. I do believe that these things will be explained in some unforeseen plot twist in the 6th or 7th book.
It is contradictions and mysteries like these that place JK Rowling as a truly interesting fantasy writer, despite some naysayers who believe that books this popular couldn't be any good.
Update: when I wrote this, there were other nodes explaining the basic nature of Albus Dumbledore, the kind and powerful headmster of Hogwarts. There still has to be a basic writeup about Dumbledore. I was also very foolish to add my spare thoughts on the possible motivations and abilities of Dumbledore. All of my radical ideas about Albus Dumbledore have already occured to others, apparently, and the amount of speculation on plot and character points in Harry Potter online is truly staggering. I can be sure, however, that Albus Dumbledore is an important character in Harry Potter, and has some twists in his story coming up.
After reading the sixths book, we have found out that there were some twists, of a nature that is sad but not totally unexpected. One of the penultimate parts of the book is seeing Albus Dumbledore fall from his position of total control into being weak, helpless, and even mentally unfit. It seems then, that the solution to the problem was that Albus Dumbledore was not quite as totally powerful as people would have thought.