Jay JG:
"Deductive reasoning" becomes original research when it is used to build a case against a position presented in an article, not when used to do unit conversions. Now if you were to assert that based on genetics and "simple deductive reasoning" that uncles were more closely related to nephews than aunts were to nieces, that would be original research, and you'd have to find some source which supported it.
Ray Saintonge:
That's certainly an extremist view. It implies that a crackpot theory is acceptable as long as it has previously been published somewhere else.
I was grateful for the clarification later given by Jay JG. Where I differ, myself, is in not taking "idea" from the policy page to mean any proposition, however concrete or factual, but to have some debatable general or abstract content (e.g. the theory of relativity).
Charles