An agent who acts intentionally typically foresees that she will bring about a number of effects and that her conduct will fall under a variety of different descriptions. Which of these effects and descriptions are intentional and which are incidental? To answer this question, Chapter 4 presents an Anscombian account of intentional action. I first show how Anscombe uses a special sense of the question “Why?” to elucidate the teleological order characteristic of intentional action. I then explain how the teleological order of an agent’s intentional action is determined by the calculation on the basis of which she acts, where the concept of calculation is illuminated by the notion of practical reasoning. Next, I explain how Anscombe’s account of intention and intentional action differs from a false conception she calls “Cartesian psychology.” Finally, I apply the Anscombian account to three controversial cases.

According to the PDE, there is a strict moral constraint against bringing about serious evil (harm) to an innocent person intentionally, but it is permissible in a wider range of circumstances to act in a way that brings about serious evil incidentally, as a foreseen but nonintended side effect. In Chapter 1, I discuss the key terms in this definition and I distinguish between an absolutist version of the PDE and a nonabsolutist one. I then introduce two principles that help guide agents when they foresee their conduct will cause incidental harm: the Principle of Proportionality and the Principle of Due Care. Finally, I describe the role of the PDE in just war theory and international humanitarian law, and I set out the plan for the remainder of the book.