This article explores the ambivalent relationship of neo-Aristotelian naturalism to ethical supervenience. One of the main proponents of this approach, Michael Thompson, holds a position that leads to a rejection of local ethical supervenience. It is argued that this rejection implicitly undermines a premise held by other prominent neo-Aristotelian naturalists, such as Philippa Foot or Rosalind Hursthouse, who implemented Thompson’s species-relative logic of ethical evaluations into their theories. This premise—that there is a systematic connection between the virtuous life and the (...) benefit of the individual—could be re-established if neo-Aristotelian naturalism abandoned the species-essentialist understanding of life-forms and instead accepted local ethical supervenience as an ethical frame of reference. Although this article derives its problem from the main works of the aforementioned authors, its interest lies not mainly in exegesis, but in the systematic discussion of the logical status and the functionality of the concept of life-form in neo-Aristotelian naturalism. This discussion will be enriched by the inclusion of the logical distinctions and insights from modern philosophical biology. (shrink)