Abstract
This essay explores the moral reasoning underpinning the common view that it is worse to kill a human compared with killing an animal. After examining the serious deficiencies of traditional approaches, the author develops an alternative utilitarian-based framework that proportions the seriousness of killing to levels of sentience. He demonstrates how this new approach avoids the problems faced by the application of standard utilitarian formulae in weighing the seriousness of killing many low-sentience animals vis-á-vis killing a single human. The author concludes with a discussion of how this new approach overcomes the difficulties faced by Peter Singer’s dualist form of utilitarianism.