Formal logic equivalent of a "self fulfilling prophecy?"

Question

For example

Will this query be answered correctly?

Yes

Has this query been answered correctly?

a) yes, therefore "yes" is the correct answer, therefore this query has been answered correctly.

b) no, therefore "no" is the correct answer, therefore this query has been answered incorrectly.

Either assumption is verified.

What is the technical term for this phenomenon, and what formalised studies exist on it? The closest I can find is the informal concept of "self fulfilling prophecy."

The negation of your statement, a "self-denying prophesy", is a particularly nasty trick which can be used to undermine some naive logics. The relevant terms here are naive set theory and Russell's paradox. Since then all popular formal systems have included mechanisms to circumvent this problem. — Mario Carneiro, Mar 07 '15 at 04:22

score 0 · Answer 1 · answered Mar 06 '15 at 18:09

0

This paradox comes from self reference. Formal logics are constructed in particular way (Tarski hierarchy of languages) to avoid self-refrence and thus such paradoxes.

answered Mar 06 '15 at 18:09

Trismegistos

2,410

Formal logic equivalent of a "self fulfilling prophecy?"

1 Answers1