The Extended Mind Hypothesis

Not sure I entirely agree with this, being the introspective fellow I am, but it is most interesting:

I actually came to the conclusion that thinking is not something done by a single person. We have a false model of what thinking is. Because you can't really think by yourself, can you? You have to create someone else in your mind to explain things to, and to have an imaginary conversation with. This idea was inspired in part by the philosopher of cybernetics, Andy Clark, who proposed something he calls the extended mind hypothesis. Basically, the argument goes like this: Say you're doing long division on a piece of paper instead of doing it in your head. Clark asks why the piece of paper is not just as much a part of your mind while you're doing that calculation as the part of your brain that's doing the math. He says there's no reason at all.There are a million similar examples that philosophers like to trundle out — you have a bad memory so you write everything down. Is that piece of paper then part of your mind?

"Mind" isn't "brain" — the brain is just an organ; your mind is the dynamic interaction of various moving elements that culminates in thought. Philosophers like Clark are willing to take that argument this far, but the question that never seems to occur to them is this: when you're having a conversation with someone else, is their mind part of your mind? Nowadays, many philosophers of consciousness like to note just how razor-thin this thing we call "consciousness", that self-aware part of our mental operations, really is. The average person can rarely hold a thought for more than three or four seconds, eight at the most, before the mind wanders. It's very unusual to be fully conscious for more than a tiny window of time. That is, unless you're having a conversation with someone else, in which case you can often do it for long periods of time, especially if the conversation is with someone you find particularly interesting. In other words, most of the time we're conscious is when we're talking to someone else, or otherwise interacting intensely; during moments in which when we're not clear whose mind is whose. So consciousness is interactive, it's dyadic or triadic. It's a fallacy to imagine that thinking is something you largely do alone. On some level, of course, we already know that. But I don't think we've even begun to explore the full implications.

From an interview with David Graeber. Yeah, I know, I'm such a fanboy.