The Mind Arts: Occlumency

Occlumency is the art, one who practices it is an Occlumens.

This is another topic on which the books themselves are either incredibly incomplete, or utterly impossible. The interview quoted at the Harry Potter fandom wiki on Occulumency¹ makes the situation worse, not better. In the interview, she is asserting that Professor Snape's description of Occulumency is accurate - that it is the practice of compartmentalizing and/or suppressing emotion and memories. This is further confirmed in her article on Draco on what used to be Pottermore.²

There are three problems with this. One, it isn't really practical. In The Grass Is Always Greener³, Daphne describes what this would be like in practice:

Keep your eyes closed and let your mind go still. You can't think of nothing for very long, therefore you must think of something. So I want you to find a memory, or really an image, of something that is very neutral, very same, very uniform, and preferably all encompassing. It can be an image of the sky, the water in the ocean if you've been there, a large table cloth that's a single color, or whatever you know and can easily pull up.⁴

Harry later figures out what this would be like to hold all the time:

Harry had been diligently practicing his clearing of the mind every spare moment he had. He was proud of himself for a small break through he had had yesterday. He had finally figured out how to find the dark blanket, as he thought of it now, and still remain "normal". The result was something like a thin black haze across his vision and slightly reduced hearing. Still, now he knew he could have something of a shield up and still know what was going on around him, unlike being blind and almost deaf the first time he had done it with Daphne.⁵

In that story, Harry chooses the "view" of a room without light - total darkness. This works, but basically means both reduced sight and, because he's partially focusing on something else, reduced awareness overall. Are you really going to duel like that, as Professor Snape suggests when fighting Harry in Chapter 28 of the Half-Blood Prince⁶? People really can't effectively multitask that way. You can concentrate on your cleared mind, or on what is happening around you (to be able to react to stray curses for example) but not on both.

Secondly, it is not even really consistent. Professor Snape is described as a master at Occulumency. However, he is constantly showing his anger, hatred, and scorn. It is not only the positive emotions that can be used against you, anger can be used against you as well. The man who cannot look past James Potter to see Harry Potter cannot depend on compartmentalization to keep his mind in control. The man who, in that same chapter, totally loses control just because Harry attempts to use his own spell⁷ is a master at emotional control? It does not make sense.

Thirdly, shutting down emotions, suppressing them, is not particularly healthy. While it is a common short term strategy, and can even be a viable one in the fact of a trama situation, long term it will cause problems with your ability to form and maintain interpersonal relationships⁸, long term health problems (probably due to stress)⁹, and others that you can find on google. Basically, it is really really bad advice for long term use. On one hand, it certainly describes Snape. On the other, is this really the recommendation that Dumbledore has for Harry, whose supposed power is love? Either it had no chance of working (which seems to be Mrs. Rowling's theory, in the Draco article, but come on, really?) in which case Dumbledore really is throwing Harry to the wolves, or Dumbledore does not really care about the damage this might do to Harry, in which case he must not really much believe his own theory about Harry's love being supper important.

The tone of the Draco article¹⁰ strongly implies that Harry had no chance of getting Occlumency to work. I think it need not have been that way, but I think it is clear at this point that the author's intent for Occlumency is fairly clear. The problem then is not so much Occlumency, but rather [Legilimency].