It is contradictory to simultaneously say “P and not-P”, but could someone coherently say “It is raining, but I don’t believe it is raining”? This odd little sentence is the heart of Moore’s paradox, what Wittgenstein thought was the most significant discovery G.E. Moore ever made as a philosopher. Moore’s sentence doesn’t strike me as obviously contradictory in the same way as “P and not-P”, but it is strange nonetheless. Presumably you would say “it is raining” when you can clearly see it is raining, so how could you not believe it? If you know it is raining such that you say it is raining, the rules of mental logic seem to suggest you should also believe it is raining, otherwise why say “it is raining”?. My solution to the riddle is that the claim about whether it’s raining is ambiguous between different criteria for satisfying the condition “it’s raining”. “It is raining” could mean that water is falling from the sky in a way that looks natural, or it could mean that natural precipitation is actually falling from the clouds. Why would you need the former locution? Suppose you work on a Hollywood set and you know that the artificial rain machines sometimes come on. All of a sudden it starts raining in the sense that water is falling from the sky in a way that looks natural (until you glance up at the giant machines). Now it becomes perfectly sensible to say “It is raining, but I don’t believe it is raining”. This in essence says “Water is falling from the sky but I don’t believe it is natural precipitation”. This is clearly a sensible thing to say in the circumstances.