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The best way to test whether a formal logical principle is correct is to see whether
{ 1 } - it's formulated using only variables and logical terms.
{ 2 } - we can derive false or absurd results from it.
{ 3 } - it's intuitively evident.
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The best way to test whether a formal logical principle is correct is to see whether
{ 1 } - it's formulated using only variables and logical terms.
{ 2 } - we can derive false or absurd results from it.
{ 3 } - it's intuitively evident.
If it can be formulated this way, then it's a formal logical principle -- but not necessarily a correct one.
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2 is correct!
The best way to test whether a formal logical principle is correct is to see whether
{ 1 } - it's formulated using only variables and logical terms.
{ 2 } - we can derive false or absurd results from it.
{ 3 } - it's intuitively evident.
Consider this proposed principle: "If A then B, B, so A." This leads to an absurd result:
If I'm in Texas, then I'm in the US.
I'm in the US.
So I'm in Texas.
Here both premises are true. But the conclusion is false -- since I'm in Chicago. So we reject the principle as leading to absurdities.
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The best way to test whether a formal logical principle is correct is to see whether
{ 1 } - it's formulated using only variables and logical terms.
{ 2 } - we can derive false or absurd results from it.
{ 3 } - it's intuitively evident.
Untrained logical intuition is poor in determining validity.
I give a logic pretest the first day of my introductory logic course. The problems are easy, but my students get almost half wrong.
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the end