Fact.

Use this word only of matters of a kind capable of direct verification, not of matters of judgment. That a particular event happened on a given date, that lead melts at a certain temperature, are facts. But such conclusions as that Napoleon was the greatest of modern generals, or that the climate of California is delightful, however incontestable they may be, are not properly facts.

From: William Strunk, Jr., The Elements of Style, 1918.