I do think so!

Posted by Sprock on November 04, 2003

In Reply to: I do think so! posted by doc on November 04, 2003

The 'not' construct appears to set up the statement that follows as a fact whose truth is commonly agreed. The question seems to be directed at questioning your agreement with this common truth, not questioning whether the fact being asserted is true. But when you start un-picking the words this is still only an appearance. It all seems to fall back on a convention of rhetorical style with no basis in the underlying logic of the words.

I started looking at the following questions:
Is it true that the sky is blue?
Is it true that the sky is not blue?
Is it not true that the sky is blue?
Is it not true that the sky is not blue?

With answers:
It is true that the sky is blue.
It is not true that the sky is not blue.
It is not true that the sky is not blue.
It is not true that the sky is not blue.

The last 3 question forms seem to collapse to the same form of answer with forms 2 and 3 needing an additional not to be added to make sense. Going down this route starts to explore the points in the web page suggested by Doc. The logic has one meaning and common usage gives a different meaning.

The original question poses additional questions. When did the meaning of this construct separate itself from the logical meaning of the words? Has it always been so? Does 'not' get used in other languages in the same way to present rhetorical questions?

Thanks for the web reference.