I just read Timothy Leary’s “Your Brain is God”. It’s an enjoyable read, just 60 pages or so, and Leary is obviously an intelligent and fairly insightful guy. I find myself pretty much agreeing with him in terms of policy prescriptions.

However, his reasoning has one big flaw that gets on my nerves. He has a tendency to be a little too eager to ascribe intentionality to things.

For example, he writes about the existence of “brain castes”. What he seems to be saying is that people’s brains are wired differently, so that they can perform different roles in society. There’s a core of cool insight here: people’s minds do work very differently, and we have a tendency to not realize that and just assume the way our own minds work is the way everyone’s do. The issue is that the causality flows the opposite way: people with minds that work in different ways do end up seeking certain roles in society, at least on average, but there’s no intentionality behind it, that’s just how people having different personality types works. He does similar things when talking about the human brain, and about the biosphere.

I feel a little bad making this argument, since it has the obvious response that he just means it metaphorically, and I’m being a spoilersport by being so literal. The problem is that I have spoken to people who do take this sort of thing literally. It’s important to make clear what’s a metaphor and what isn’t – just ask whoever wrote the bible.