 Second, some adopt a version of the “precautionary principle”. To introduce this principle it is helpful to turn to Neil Manson’s excellent analysis of the precautionary principle (Manson 2002). Manson argues that all formulations of the precautionary principle contain three elements. In particular they include what he terms “a damage condition” (this states what kinds of bad outcomes are relevant), a “knowledge condition” (this states what kind of epistemic conditions are required—is it uncertainty or a certain level of risk?) and a “remedy” (this states the right response) (Manson 2002: 265). The central idea is that when people are engaged in a certain kind of action in which there is a prospect of harms of the relevant kind, and when our understanding of whether the harms will materialise satisfies the knowledge condition, then it is appropriate to adopt a precautionary policy (Manson 2002: esp. 265). Clearly, however, a great deal of work is needed to specify the three core features—how much harm and what kind of harm is relevant?; what epistemic conditions must hold?; what course of action is required (Manson 2002: 267)? 