So I'm sitting around a table with a bunch of my fellow Cognitive Science PhD students. One of them says something about not being about to make up her mind. Another one says something like "You're a Libra, aren't you? That's so like a Libra."

Yeah, I can't keep my mouth shut on that topic when it pops up. So we launch into this whole discussion, and basically three of the students (all women) were defending astrology to greater or lesser degrees, and the other two were relatively quiet.

First I was told that we don't have a good way to describe collections of personality types, and that astrological signs are a replacement for that. I said that was a decent point...we don't really have good concepts for people who have a group of personality traits. But I asked if you'd ever say a person not born under Libra was basically a Libra-like person, and was told no, that there was this correlation and that a non-Libra would ever act like a Libra. Oooookay.

So I said it was hooey to believe that everyone born during the same month had the same personality (just as it would be hooey to say that everyone born in the same year--Chinese zodiac--had the same personality), but they were having none of it.

I got the "science can't explain everything, you know". Hmm, no shit. Any scientist will readily admit that there's lots of stuff science can't explain. They're called open questions. So I asked them if they really thought a causal link between personality and birthdays was an open scientific question, and basically got a yes.

I wanted to cry, I really did. These are supposed to be budding scientists.

I also asked how you separate good beliefs from bad ones, and was told "there are no bad beliefs; everyone uses them in their own way". Then the conversation kind of fell apart...people from the other end of the table had to go.

But I've talked about this here before, and doubtless will again.

Is believing that the Holocaust never happened as good a belief as a belief that it did? Is believing that some races are subhuman not a dangerous and bad belief? Or that women are inferior? Pick your favorite spurious belief. Beliefs have consequences. The idea that whatever someone else believes has no consequences is itself a dangerous idea.

Less superstition and ignorance, and more common sense and rationality, lead to societies where fewer judgements are made on misinformation and inaccurate beliefs, and that's better for everyone, is it not?