Deep Uncertainty and Incommensurability: General Cautions about Precaution

Abstract The precautionary principle is invoked in a number of important personal and policy-related decision contexts. Peterson shows that certain ways of making the principle precise are inconsistent with other criteria of decision making. Some object that the results do not apply to cases of deep uncertainty or value incommensurability, which are alleged to be in the principle’s wheelhouse. First, I show that Peterson’s impossibility results can be generalized considerably to cover cases of both deep uncertainty and incommensurability. Second, I contrast an alternative way of giving voice to the precautionary impulse.