Curry sentences are of the form:
- If (1) is true, then p,
- If not-p, then (2) is not true.
Now, go back to my old favorite, the contingent liar paradox. There are many versions. One of them is this. Let D be some definite description of a sentence which picks out different sentences in different worlds. Then consider:
- The sentence satisfying D is not true.
- The contingent liar (3) is unparadoxical if D picks out a first-order sentence that is unproblematically true or unproblematically false, in which case (3) has the opposite truth value to that of that sentence.
- The following sentence is not true: "1=1" if p and (5) if not-p.
- "1=1" is true if p, and (6) is not true if not-p.
- Sentence (7) is not true if not-p.
But we ought to say the same thing about (2) as we say about (7), and about (1) as about (2). So, the Curry sentence (1) is unparadoxically true if p. And if p is false, it is a liar sentence, and a contingent liar sentence if p is contingently false. All this means that the Curry paradox is not very different from the contingent liar.