loqi comments on What's in a name? That which we call a rationalist… - Less Wrong

4 Post author: badger 24 April 2009 11:53PM

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Comment author: loqi 25 April 2009 03:46:00AM 3 points [-]

I've been thinking "evidentialist" was a good label, and I finally just bothered to google it. Nothing on its wikipedia page looks particularly objectionable (and if the objections were minor, its small footprint suggests hostile namespace takeover is possible). Thoughts?

Comment author: badger 25 April 2009 04:21:18AM 1 point [-]

I like this. It is a little awkward, but evidentialism appears to be very close to what we mean by epistemic rationality here. I'd be interested to hear if someone has an idea how Bayesian priors might fit in with evidentialism. My guess is that an evidentialist would say that pure priors are not justified, but gain justification as you incorporate more evidence in. However, we do generally have a sense that some priors are better than others. Is that belief justified by evidence?

Comment author: loqi 25 April 2009 05:46:50PM 0 points [-]

My guess is that an evidentialist would say that pure priors are not justified, but gain justification as you incorporate more evidence in.

That sounds right to me, except that it's not really the priors gaining justification, it's the posteriors. Subtracting the prior from the end result wouldn't change the level of justification.

However, we do generally have a sense that some priors are better than others. Is that belief justified by evidence?

A tricky question. Our belief about a prior is different than the prior itself. So we may have a justified belief about a prior (e.g., we have evidence that we live in an ordered universe, so Occam priors have a head start), but we can't exactly "use it" on priors, because that just generates a posterior.

I feel a bit uncomfortable bandying about the word "justification" as if it's a useful primitive. As a label, I like "evidentialist" more for its immediate connotative value than for the final result of peeling through layers of arbitrary philosophical wordplay involving things like "justification" to see what we find. Evidence at least has a clean, useful definition under the Bayesian umbrella.

Comment author: Jack 25 April 2009 04:01:07AM 0 points [-]

Well I'd reprise my objection to stealing the names of obscure-among-the-general-population theories of epistemology. And if you don't care about that objection then I think rationalist has the edge over evidentialist. It's also awkward sounding and I'm not sure it captures the feel of what we're doing. Our concern hasn't been with the evidence so much as how the evidence is processed.

Comment author: loqi 25 April 2009 05:57:09PM 1 point [-]

I find both terms a bit awkward, neither completely satisfactory in a denotative sense (they don't hold a candle to "Bayesian" in that regard). I think rationalist comes off as a bit more hubristic. Naming ourselves does draw artificial lines, implying that we're "more of that" than others. So when we call ourselves rationalists, we imply that the other party is irrational. When we call ourselves evidentialists, we imply that the other party isn't paying enough attention to evidence. The latter seems less immediately offensive, and I would expect a less defensive reaction in turn.