CHRISTIAN MUNTHE The Price of Precaution and the Ethics of Risk. Springer, .  pp. ISBN - (hardback). reviewed by Niklas Möller, Division of Philosophy, KTH Royal Institute of Technology, Stockholm IN THE FACE of potentially severe hazard, we should act with precaution. This idea forms the base of what is commonly called the Precautionary Principle (PP), one of the most popular norms in the risk policy debate. Many scholars see PP as deeply problematic, however.There are many alternative formulations of the principle in the debate, and critics claim that it is either too unclear to give us any action-guidance, or lacks proper justification. In The Price of Precaution and the Ethics of Risk, Christian Munthe responds to this criticism by putting forward an ambitious defence of an ideal of precaution, which he aims to show is justified, sufficiently clear and practically useful. Munthe argues that such an ideal, which he calls the requirement of precaution, must tell us how much we should be prepared to sacrifice in terms of increased cost, present harms and new threats. Several alternative suggestions for how to justify such a price of precaution are discussed – and rejected – in favour of Munthe’s explicitly moral theory about precaution. Our moral responsibility in relation to risk impositions, he ultimately argues, prescribes that we put a greater moral weight on potential harms than on benefits. Furthermore, those extra negative weights to harms should be proportional to their magnitudes as well as contextual in the sense that they should be relative to what other harms and benefits are at stake. Munthe argues that even if his requirement remains somewhat vague, it is still practically useful. Indeed, he ends the book with a chapter demonstrating the (often far-reaching) practical consequences of the theory, applying it to a number of actual cases – climate change, pollution, energy production and biotechnology – as well as addressing policy questions in a national context. Munthe’s argumentation covers decision theory, ethics and practical applica- tions. This ambitious strategy is motivated by Munthe’s methodological commit- ment, which starts out from the presumption that much of the current criticism of the precautionary principle is the result of too much conceptual analysis and too little normative analysis. What is at stake in the debate “is not primarily what PP or the word ‘precaution’ means, but what requirements environmental and technologi- cal policy making should meet” (p. 20). The conceptual and justificatory work, Munthe concludes, must be done in tandem. Munthe takes this justificatory task seriously throughout, investigating several potential sources of justification before settling on his own alternative. THEORIA, 2013, 79, 89–92 doi:10.1111/theo.12004 © 2013 Stiftelsen Theoria. Published by Blackwell Publishing, 9600 Garsington Road, Oxford OX4 2DQ, UK, and 350 Main Street, Malden, MA 02148, USA.