gwern comments on Rationality Quotes April 2012 - Less Wrong

4 Post author: Oscar_Cunningham 03 April 2012 12:42AM

You are viewing a comment permalink. View the original post to see all comments and the full post content.

Article Navigation

Comments (858)
Tags: quotes

Comments (858)

You are viewing a single comment's thread. Show more comments above.

Comment author: Alejandro1 03 April 2012 05:01:58PM 17 points [-]

‘I’m exactly in the position of the man who said, ‘I can believe the impossible, but not the improbable.’’

‘That’s what you call a paradox, isn’t it?’ asked the other.

‘It’s what I call common sense, properly understood,’ replied Father Brown. ’It really is more natural to believe a preternatural story, that deals with things we don’t understand, than a natural story that contradicts things we do understand. Tell me that the great Mr Gladstone, in his last hours, was haunted by the ghost of Parnell, and I will be agnostic about it. But tell me that Mr Gladstone, when first presented to Queen Victoria, wore his hat in her drawing-room and slapped her on the back and offered her a cigar, and I am not agnostic at all. That is not impossible; it’s only incredible.

-G. K. Chesterton, The Curse of the Golden Cross

Comment author: gwern 04 April 2012 12:57:19AM 8 points [-]

The ghost of Parnell is Far, the presentation to the Queen is Near?

Comment author: Alejandro1 04 April 2012 03:34:04AM *  2 points [-]

Perhaps. I had thought of the quote in the context of a distinction between epistemic/Bayesian probability and physical possibility or probability. For us (though perhaps not for Father Brown) the ghost story is physically impossible, it contradicts the basic laws of reality, while the presentation story does not. (In terms of the MWI we might say that there is a branch of the wavefunction where Gladstone offered the Queen a cigar, but none where a ghost appeared to him.) However, we might very well be justified in assigning the ghost story a higher epistemic probability, because we have more underlying uncertainty about (to use your words) Far concepts like the possibility of ghosts than about Near ones like how Gladstone would have behaved in front of the Queen.

Comment author: cousin_it 04 April 2012 09:50:05AM *  1 point [-]

I seem to instinctively assign the ghost story a lower probability. The lesson of the quote might still be valid, can you come up with an example that would work for me?

Comment author: Alejandro1 04 April 2012 03:50:24PM 1 point [-]

Sure. Take one mathematical fact which the mathematical community accepts as true, but which has a complicated proof only recently published and checked. Surely your epistemic probability that there is a mistake in the proof and the theorem is false should be larger than the epistemic probability of the Gladstone story (if you are not convinced, add more outrageous details to it, like Gladstone telling the Queen "What's up, Vic?"). But according to your current beliefs, in the actual world the theorem is necessarily true and its negation impossible, while the Gladstone story is possible in the MWI sense.

Powered by Reddit Powered by Reddit