You're looking at Less Wrong's discussion board. This includes all posts, including those that haven't been promoted to the front page yet. For more information, see About Less Wrong.

jklsemicolon comments on You only need faith in two things - Less Wrong Discussion

22 Post author: Eliezer_Yudkowsky 10 March 2013 11:45PM

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

Comments (86)

You are viewing a single comment's thread.

Comment author: jklsemicolon 11 March 2013 03:07:25AM 7 points [-]

that some single large ordinal is well-ordered

An ordinal is well-ordered by definition, is it not?

Did you mean to say "some single large ordinal exists"?

Comment author: Eliezer_Yudkowsky 11 March 2013 05:57:09PM 2 points [-]

Yeah, it's hard to phrase this well and I don't know if there's a standard phrasing. What I was trying to get at was the idea that some computable ordering is total and well-ordered, and therefore an ordinal.

Comment author: drnickbone 12 March 2013 07:34:29PM 0 points [-]

Well, supposing that a large ordinal exists is equivalent to supposing a form of Platonism about mathematics (that a colossal infinity of other objects exist). So that is quite a large statement of faith!

All maths really needs is for a large enough ordinal to be logically possible, in that it is not self-contradictory to suppose that a large ordinal exists. That's a much weaker statement of faith. Or it can be backed by an inductive argument in the way Eliezer suggests.