This book is a critique of rationalism. It aims to explain both its powerful contributions to mathematics and physical sciences, where our arithmetical, geometrical, and mechanical intuitions have had a highly productive role in the development of pure theory, and its disastrous failures in cosmology and the moral sciences. In these supposed sciences, rationalism has all but destroyed the social conscience of the West, by creating the disastrous political philosophy of neoliberalism. To reset our moral compasses, we must develop new, and socially just versions, of the old welfare states. And, to restore democracy, we must return to Keynesian economic management.