I'm not sure if I should post this here, but here goes: I'm trying to determine whether this proposition: is itself uncertain, or it doesn't refer to reality. Here are my thoughts: if we let p := "the laws of mathematics refer to reality" q := "they are certain" Then the proposition becomes: if p then ~q and if q then ~p But this is a mathematical proposition (if we include first order logic to mathematics) By its own standard, if it refers to reality then it is not certain And if it is certain, then it does not refer to reality. Am I correct in this or is there a mistake in the argument? I'm really not sure whether it is a mathematical proposition in itself, but from the discrete math I've taken, first order logic is usually thought part of math, even a foundation of math. Or maybe because it does not convert to a math proposition the way I've done so. What are your thoughts?