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.

Manfred comments on Truth and the Liar Paradox - Less Wrong Discussion

4 Post author: casebash 02 September 2014 02:05AM

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

Comments (43)

You are viewing a single comment's thread.

Comment author: Manfred 02 September 2014 02:43:32AM 4 points [-]

Next we consider, "This statement is true". Setting the truth value to false would lead to a contradiction

Nope. If it is false, then "this statement is true" is false, no flip-flopping. Also note that this is an example that remains undefined under Prior's proposal.

Different assignments of true and false being possible is closely related to model theory, which you might want to look into. (See also some of So8res' posts)

Multiple truth assignments is also symptom of unprovability, which brings us into the realm of the incompleteness theorem. Work in this area demonstrates why type theory is not sufficient to prevent self-reference. Definitely worth learning more about the incompleteness theorem.

Comment author: casebash 02 September 2014 02:58:53AM 1 point [-]

Oh and I've updated it to use the statement, "This statement is true or false".