“Acceptable Risk” – On the Rationality (and Irrationality) of Emotional Evaluations of Risk What is “acceptable risk”? That question is appropriate in a number of different contexts, political, social, ethical, and scienti c. Thus the question might be whether the voting public will support a risky proposal or project, whether people will buy or accept a risky product, whether it is morally permissible to pursue this or that potentially harmful venture, or whether it is wise or prudent to test or try out some possibly dangerous hypothesis or product. But complicating all of these queries, the “sand in the machinery” of rational decision-making, are the emotions. It is often noted (but too rarely studied) that voters are swayed by their passions at least as much as they are convinced by rational arguments. And it is obvious to advertisers and retailers that people are seduced by all sorts of appeals to their vanities, their fears, their extravagant hopes, their insecurities. At least one major thread of ethical discourse, the one following Kant, minimizes the importance of the emotions (“the inclinations”) in favor of an emphatically rational decision-making process, and it is worth mulling over the fact that many of those who do not accept Kant’s ethical views more or less applaud his rejection of the “moral sentiment theory” of the time, promoted by such luminary philosophers as David Hume and Adam Smith.