The ‘doctrine of double effect’ claims that it is in some sense morally less problematic to bring about a negatively evaluated state of affairs as a ‘side effect’ of one’s pursuit of another, morally unobjectionable aim than it is to bring it about in order to achieve that aim. In a first step, this chapter discusses the descriptive difference on which the claim is built. That difference is shown to derive from the attitudinal distinction between intention and ‘acceptance’, a distinction that is in turn claimed to ground in a feature of the decisions that generate the attitudes in question. The resulting analysis is then plugged into two different normative principles that may each be thought to specify the int...