Stating an unproven negative holds the same value to me as stating an unproven positive. That's a fact and that's exactly what I said.

Stating an unproven negative as if it were a fact is also not the best scientific approach.

(Also, saying something like "the mind has no affect on the body" is a positive statement of fact. Quibbling about the word "no" or "not" is just semantics IMO.)