RE: The Limits of Logic #3

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For the raining/cloudy example, try thinking about another one:

All triangles are 3-sided
Not a triangle -> not 3-sided



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Again, I think the order is critical and the correct statement would be:
All triangles are 3-sided
not 3-sided -> not a triangle

For instance, a shape with 3 curved sides is not a triangle, but it is 3-sided

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Okay, so let's see:

All triangles are 3-sided

A -> B

not 3-sided -> not a triangle

~B -> ~A

squares are 4-sided

C -> D

not 4-sided -> not a square

~D -> ~C

A square -> not 3-sided

C -> ~B

a 4-sided object -> not a triangle

D -> ~A

So everytime we see a non 3-sided object (because it is 4-sided) it is reinforcing the idea that it is not a triangle (it is a square)

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Then going further, we could say that a pentagon (which is non 3-sided) implies that it is not a triangle. But if that is true, it would be equivalent to saying that triangles imply they are pentagons, or all sorts of other crazy things.

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Yes, absolutely, I agree the paradox is really quite interesting. By reasoning logically, one can end up with an obviously unrelated statement supposedly supporting the original statement. Like I said, I like these logic oddities. Thanks for writing about this paradox.

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