ABSTRACT
This chapter argues that the assumption that there is a distinct class of placebo effects that is usefully identified for inquiry and treatment is unfounded. It presents cases offered as placebo effects in the literature and suggests that characterizations of the placebo effect are subject to insurmountable scope problems. The chapter discusses identifying the placebo effect in the literature as being useful for three purposes: randomized controlled trials; mechanistic inquiries; and treatment. The utility of identifying some effects as placebo effects may initially seem supported by the increasing number of multidisciplinary inquiries into such effects. The chapter also suggests that beliefs according to which some processes are bottom up while others are top down sometimes contribute to the intuition that some token or type of top-down processing effect is a placebo effect. Background beliefs about beliefs play a large role in non-expert intuitions about the placebo effect. Background beliefs about which interventions are legitimate are key contributors to placebo-effect intuitions.
