Abstract The social engagement on which Buchanan has placed his focus is particularly important to bear in mind in solving the problems that the world faces today. Whether we are concerned with global warming or other environmental challenges, or with crippling unemployment and a stalled economy, the need for interactive public reasoning has never been stronger. The cultivation of the taste for public reasoning in an open-minded way, which James Buchanan has done so much to advance, is one of the features of his greatness for which economists and other social scientists—and indeed the world at large—have much reason to be grateful.