The Enlightenment and Social Choice Theory∗

The enlightenment was a philosophical project to construct a rational society without the need for a supreme being . It opened the way for the creation of market democracy and rapid economic growth. At the same time economic growth is the underlying cause of climate change, and we have become aware that this may destroy our civilization. The principal underpinning of the enlightenment project is the general equilibrium theorem (GET) of Arrow and Debreu (1954), asserting the existence of a Pareto optimal price equilibrium. Arrow’s work in social choice can be interpreted as an attempt to construct a more general social equilibrium theorem. The current paper surveys recent results in social choice which suggests that chaos rather than equilibrium is generic. We also consider models of belief aggregation similar to Condorcet’s Jury theorem and mention Penn’s Theorem on existence of a belief equilibrium. However, it is suggested that a belief equilibrium with regard to the appropriate response to climate change depends on the creation of a fundamental social principle of "guardianship of our planetary home." It is suggested that this will involve conflict between entrenched economic intrests and ordinary people, as the effects of climate change make themselves felt in many countries. JEL classification: H10