Thursday, July 8, 2010

You can't prove a negative? Who says?

According to a distressingly common urban legend, some law of logic holds that you can't prove a negative. A little reading in philosophy would show that no such law of logic exists. For one thing, how would you go about proving that you can't prove a negative, since the statement that you'd have to prove is itself a negative?

Moreover, as a practical matter, we prove negatives all the time. I routinely have to do so in my job. Typically, disproving a proposition B requires nothing more than submitting A into evidence, where A => ~B.

(Oops, my bad -- We're supposed to be talking about Lady Gaga now, aren't we?)

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