Less Wrong: Open Thread, September 2010

matt

This thread is for the discussion of Less Wrong topics that have not appeared in recent posts. If a discussion gets unwieldy, celebrate by turning it into a top-level post.

That comment leaves me wondering what "pure Bayesianism" is.

I don't think Bayesianism is a recipe for action in the first place - so how can "pure Bayesianism" be telling agents how they should be spending their time?

I don't think Bayesianism is a recipe for action in the first place - so how can "pure Bayesianism" be telling agents how they should be spending their time?

It tells them everything. That includes inferences right down to their own cognitive hardware and implications thereof. Given that the very meaning of 'should' can be reduced down to cognitions of the speaker Bayesian reasoning is applicable.

2Perplexed16y

By "pure Bayesianism", I meant the attitude expressed in Chapter 13 of Jaynes, near the end in the section entitled "Comments" and particularly the subsection at the very end entitled "Another dimension?". A pure "Jaynes Bayesian" seeks the truth, not because it is useful, but rather because it is truth. By contrast, we might consider a "de Finetti Bayesian" who seeks the truth so as not to lose bets to Dutch bookies, or a "Wald Bayesian" who seeks truth to avoid loss of utility. The Wald Bayesian clearly is looking for a recipe for action, and the de Finetti Bayesian seeks at least a recipe for gambling.