[armchairhacker]

Humanities aren't science but still important in making rational decisions. "History repeats itself" at least partially, and history/politics/religion help explain human psychology, if you look into the motives behind them.

[ncphil]

The Humanities are _essential_ to making rational decisions outside (and sometimes within) the sciences. Thomas Kuhn's work used to be viewed as a "bridge" between them (history + sociology of science). But in fact modern science owes its existence to the humanists of the Renaissance. Of course the really hard problems aren't scientific, or amenable to scientific solutions: war and peace, politics and crime, social movements, religion, economic exploitation and the ultimate questions of "why?" and "what's next?" Those require answers from history, literature, philosophy, art and culture. That's why Newton only spent the first part of his life studying the physical world, the latter part had him searching for meaning in the metaphysical.