Philosophers of science have known for decades that there are no such thing as "the plain facts" apart from theories. But the naive view that, say evolution is "just a theory" and not a fact (or the opposite view that it is now a fact and therefore no longer a theory!) p-ersist. One place they do is in detective fiction. Sir Arthur Conan Doyle famously had Sherlock Holmes resist "theorizing in advance of the facts." Maybe OK in 1890, but there is no excuse for P.D. James, writing in 2005 (The Lighthouse) to say something like "You were supposed to be giving the facts. You've strayed into supposition." Facts are just suppositions we believe in very strongly, while suppositions are just tentative candidates to be facts. The idea that a detetive (or a scientist) could wander around collecting the "facts" about a case in the absence of any theory is absurd. The very decision as to what a "fact about the case" is is a theoretical decision -- otherwise, the detective would have to just collect every fact about everything -- Carl Yastremski's lifetime batting average, the height of the Washington Monument, the effective dosage of LSD, the name of Jefferson's children, the number of traffic lights in New York City, etc. -- and hope a theory just pops out of the jumble.
Posted by Gene Callahan