Ah, but even seemingly trivial formulas like 2+2=4 can be quite nontrivial; it took the mathematicians Alfred North Whitehead and Bertrand Russell more than 300 pages in the Principia Mathematica to prove from first principles the simpler statement "1+1=2."

This is beside my point though; just because we have a definite answer to the question does not mean that we fully understand the question. For instance, the question "what color is the cloudless daytime sky?" has an obvious definite answer to those who can see it--blue. However, an unconvinced blind man might ask you to prove that the sky is blue from first principles. Proving that the sky is blue will take more work and require an understanding of the physics behind the scattering of light.

The point of constraining the question is not to get a universal answer that fits all situations, nor is it to immediately convince everyone; the point of the exercise is to better understand the question, the possible contexts in which the question can be framed, and the points on which people disagree.

Perhaps I should explain where I'm coming from; when entering a debate, my main goal is not to convince everyone that my argument is valid, but to learn something or to assess the degree to which I understand a topic. If I learn something (or discover a flaw in my understanding) by revisiting a seemingly trivial question with a definite answer, then I don't consider it pointless to debate it.