Ethan
Reputation
358
Top tag
Next privilege 500 Rep.
Access review queues
 Jun 17 awarded Favorite Question Feb 24 awarded Notable Question Jun 14 awarded Good Question Nov 9 awarded Yearling Jan 11 awarded Popular Question Jun 28 awarded Scholar Jun 28 accepted In classical logic, why is $(p\Rightarrow q)$ True if both $p$ and $q$ are False? Jun 28 comment In classical logic, why is $(p\Rightarrow q)$ True if both $p$ and $q$ are False? I had been reading line 3 (and 4 for that matter) as 'if p were to be true, then q', then inspecting the value of p, setting it to true, and then evaluating the statement. Line 3 leaves (T,T) => T like line 1, so no problem. Line 4 leaves (T,F) => T unlike line 2 (T,F) => F, so a problem. Jun 28 awarded Supporter Jun 28 comment In classical logic, why is $(p\Rightarrow q)$ True if both $p$ and $q$ are False? Thinking of it as a promise and that you are evaluating the promise itself and not the causality is extremely helpful. Thanks a lot. Jun 28 awarded Nice Question Jun 28 awarded Announcer Jun 28 awarded Student Jun 28 asked In classical logic, why is $(p\Rightarrow q)$ True if both $p$ and $q$ are False?