What is the problem of replaceability?

Singer’s much-discussed replaceability argument states that non-self-conscious animals may be killed and replaced by new animals that will lead equally valuable lives. If sound, this argument can be used to justify the cycle of raising and killing animals for food. Thus, many have argued that Singer’s theory, and utilitarianism in general, while committed to this argument, offers inadequate protection to animals. However, some utilitarians reject the argument and Singer himself was rather tentative in preventing its additional application to self-conscious beings. This tension, within utilitarianism, about how to best deal with the argument is the core of what I call “the problem of replaceability”. My main goal here is to provide a precise description of this problem. Firstly, I distinguish between the general question of replacement permissibility and the specific question of whether (a certain version of) utilitarianism implies the replaceability argument. Focusing on the specific question I set the problem apart from other known objections to utilitarianism, like the value receptacles objection and some replacement-like difficulties. I also compare two versions of the replaceability argument and advance a better one. Finally, I point out how different interpretations of the argument affect the way out of the problem. I hope this understanding of the problem offers helpful insight to possible solutions and to further investigate its importance to animal food production and animals’ moral status.