A Keynesian critique of the new enfant terribles of quantitative finance

The paper evaluates criticism on the part of the authors Nassim Taleb and Elie Ayache, directed at mainstream quantitative finance theory and practice. In particular, it examines the philosophical basis for these attacks, comparing each with the alternative afforded by Keynesian conceptions of decision-making under uncertainty. While Taleb's concerns are congruent with Keynesian conceptions of uncertainty, it is argued that Ayache has no grounds for distinguishing in a Keynesian manner between short-run and long-run expectations, due to the fact that he bases his arguments on a radically skeptical approach informed by the Speculative Realism of Quentin Meillassoux.