Abstract

The ethical significance of an agent's intention in acting has been of interest to philosophers at least since the time of Thomas Aquinas . Especially important to many thinkers has been the question of whether intentionally causing harm as a means to some good is more ethically problematic than causing harm as a foreseen-but-not-intended side-effect of the pursuit of a good. According to the principle of double effect , it is permissible to bring about a significant harm only if four conditions are met: The harm is not intended as the end of the agent's act. The act is not bad in itself . The harm is not intended as a means to the good the agent pursues. The agent has a sufficiently serious moral reason for acting. ;The first chapter of the dissertation is introductory. It briefly describes PDE and its most common applications and explains why the issues connected with the principle, and especially with its intended-versus-foreseen distinction are important to contemporary ethics. Chapter Two surveys the history of PDE from the time of Aquinas through the twentieth century. ;The third chapter gives my own account of PDE, based on the classical accounts of Aquinas and nineteenth-century theologian J. P. Gury. I discuss the proper interpretation of each condition of PDE and give preliminary arguments for the ethical relevance of the I/F distinction. ;The fourth and fifth chapters address recent criticisms of PDE. Chapter Four deals mainly with criticisms of PDE's requirement that the harm not be intended as a means to the agent's end. Chapter Five addresses criticisms alleging that the distinction between intention and foresight is unclear. ;Chapter Six considers the limits of PDE: its significant but limited role within a more comprehensive ethical theory, its inability to prescribe a particular act, and its limited application to legal matters because of the privacy of intention. Finally, Chapter Seven summarizes the main points of the dissertation and suggests directions for further research