There is a principle, the Principle of Double Effect (PDE), which is often invoked in connection with a number of bioethical issues, including abortion, the risks of medical experimentation, and, most of all, it seems, with euthanasia. According to this principle there are circumstances under which we may make what are apparently exceptions to absolute moral rules. For a great many people, the prohibitions against suicide or causing or permitting the death of an innocent person are absolute. Should all forms of euthanasia (or, for that matter, suicide) be covered by such an absolute prohibition? Or might the nature of an individual case be counterindicative of an absolute prohibition? The PDE may offer us some needed leeway.

Here I explicate the PDE in concrete application rather than only in the abstract, endeavoring to indicate the reasons for there being such a principle, to indicate some of its weaknesses, and also to indicate its major source of strength – proportionality – a feature that is not often properly appreciated. However, though I will be discussing the PDE in application to euthanasia, I will discuss it in such a way as to explicate its rationale and to illuminate its principal strengths and weaknesses as they might arise in any area of application. I argue toward the conclusion that what gives proportionality and the PDE such credibility as they have is that they allow the imperative of life affirmation to have some force in the face of moral absolutism. By life affirmation I mean an attitude of protecting and promoting the integrity and coherent functioning of life. This will be discussed in more detail in a subsequent chapter.