The dilemma objection charges that ‘weak’ versions of the precautionary principle (PP) are vacuous while ‘strong’ ones are incoherent. I respond that the ‘weak’ versus ‘strong’ distinction is misleading and should be replaced with a contrast between PP as a meta-rule and PP proper. Meta versions of PP require that the decision-making procedures used for environmental policy not be susceptible to paralysis by scientific uncertainty. Such claims are substantive because they often recommend against basing environmental policy decisions on cost–benefit analysis. (...) I argue that the second horn of the dilemma fails as a result of disregarding the role of proportionality in applications of PP. (shrink)