TTI Forums

There is a discussion going on one of the intro threads about proving a negative. I'm going to move it here so we don't distract from that thread's purpose. I'm sure most of you have seen this interview Rand did with Donahue, but it touches on the points that were being talked about in the original...

There are things that can't be proven but solely because it is a negation does not mean it can't be. Observe: Proposition: There are no even prime numbers greater than than two. This is a sufficiently "negative" statement, yes? Proof: Assume there was an even prime number greater than two....

Calderac wrote:You are never called upon to prove a negative. That's a law of logic.

It's quite possible to prove a negative. There are many ways of doing so, one of the most common is to show that if one assumes the logical inverse of the negative to be true, it would lead to a contradiction.