To London, and a lecture at the LSE by Katalin Farkas on Extended Selves.

Katalin is a philosophy professor, and presented an interesting theory: the mind is composed of two sets of features, the stream of consciousness (everyday meanderings that bubble up and away) and what she calls "standing features": the long-held beliefs, desires, etc., which define us. When we're asleep, the former shuts off, the latter persists: we are still ourselves when unconscious.

So her thesis (the Extended Mind, or EM thesis) is that we are a set of beliefs or dispositions, and where these dispositions are stored makes no difference to whether they are beliefs: a man with poor memory who documents his beliefs in a notebook and retrieves them from there. This is controversial because the notebook is outside his brain ("spacial extension", as Katalin referred to it), but we accept prosthetic limbs, so this shouldn't be a problem. And what if the notebook were inside the cranium, would that make a difference?

How far can this go? Consider a student who passes her exams with the aid of a 24/7 consultant: she understands what she's writing but didn't originate it. The consultant is effectively an external prop. This might be morally problematic today, but many of us outsource some of our beliefs in specialist areas to specialists: you could consider accountants to be a repository of outsourced beliefs.

If the EM thesis is correct, the value of certain types of expertise may change over time. We see this happen today - like it or not! - with spelling, or driving directions. What it takes to be an expert changes, with the addition of expert devices. Katalin spoke about "diminished selves", which troubled me slightly: I couldn't help wondering if she would have considered our species to have diminished when we invented language, or the written word, and could start transmitting, storing and outsourcing our knowledge.

And I also observed that the problem many people have with digital prostheses might relate to lack of control over them: they require electricity or connectivity to function; they don't self-maintain as the human body heals, and the data flowing through them might be subject to interception or copying.

Interesting stuff, and the evening ended with a quite lively discussion between the audience and Professor Farkas...