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To: philman_36

h/t to Larry - Moe and Curly (and maybe others) for catching this. (STOLLEN / MODUS TOLLENS)

The argument in the meme is INCORRECT.

It says that if P is false, then Q is false. Not so.

The correct logic says that if Q is false, then P is also false.

Example:

P = it is sunny.
Q = I go to the beach.

(If P, then Q.) If it is sunny I go to the beach.

(If Q is false, then P is also false.) This means that it is true that if I did not go to the beach, then it was not sunny.

It is NOT (necessarily true) that if it is not sunny I did not go to the beach. Because the original statement says nothing about what I might do if it is not sunny. Perhaps on some non-sunny days I go to the beach on on some I don’t. It only asserts that I’m for sure at the beach if it’s sunny.


1,093 posted on 08/24/2023 8:02:51 AM PDT by generally ( Don't be stupid. We have politicians for that.)
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To: generally
Re: Mind your P's and Q's...

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🐷
1,129 posted on 08/24/2023 10:01:20 AM PDT by Porkchop
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