No gentlemen are bankers

Pure logic, according to Ernest Nagel (and James Newman) at least. In the classic book on Gödel's theorem the following example appears:
Where g stands for gentlemen, p for polite, and b for bankers, with the bar on top meaning not. So gentlemen are contained in polite, bankers are contained in not-polite, so it follows that gentlemen are contained in not-bankers. Of course you can substitute polite with other epithets. But they got it right. As I said, it's pure logic.


  1. The logic is wrong.
    Consider the follow and tell me where the trick is:
    But that is only true if X=mortal; not if X=Greek


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