Let's take a look at some conventional wisdom.

Haven't we all heard (many times) that "You can't prove a negative"? Like so much conventional wisdom, this is errant nonsense.

For example, it wouldn't be too hard for me to prove that I didn't assassinate Abraham Lincoln (I wasn't alive then). Or, If you have a car that is certified to be a Chevy, I can prove it is not a Ford. This follows from the "Three Laws of Thought."

1. The law of identity: A thing is what it is. It can't be something else, at the same time, and in the same respect.

P = P
(not P) = (not P)

2. The law of noncontradiction: A thing cannot be both true and false at the same time.

Not ( P and (not P) )

3. The law of the excluded middle: Either P is true or P is false; one or the other, but not both at the same time.

P or (not P)

How about this one: The Red Sox didn't win the World Series in 1996. (They weren't in it.)

But here's the capper. The very statement that "You can't prove a negative" is itself a negative!! So, whoever thought of this gem was asserting something that he himself said could not be proven.

We'll be attacking more conventional wisdom in future columns.