Introduction

This introduction presents an overview of the concepts discussed in the subsequent chapters of this book. The book focuses on the medieval philosopher and theologian Thomas Aquinas. It aims to provide some deficiencies of historical overviews of the development of the principle of double effect. The book summarizes the individual formulation of the principle of double effect and demonstrates that they are set in different ethical systems in which they often play very different roles. Advocates of the principle of double effect usually regard hysterectomy as licit, but they reject the possibility of craniotomy, since the physician’s intention in the medical procedure is killing the foetus. In the context of modern palliative care the double effect principle is most commonly mentioned in connection with administering opioids at the end of life when they can affect the patient’s respiratory drive and thus have the potential to shorten her life.