Is the Neo-Aristotelian Concept of Organism Presupposed in Biology?

Abstract

According to neo-Aristotelian ethical naturalism, moral goodness is an instance of natural goodness, a kind of normativity supposedly already present in nature in the biological realm of non-human living things. Proponents of this view appeal to Michael Thompson’s conception of a life-form–the form of a living organism–to give an account of natural goodness. However, although neo-Aristotelians call themselves naturalists, they hardly ever consult the science of biology to defend their commitments regarding biological organisms. This has led many critics to argue that the neo-Aristotelian account of natural normativity is out of touch with the findings of modern evolutionary biology. One line of response to this objection, presented by John Hacker-Wright and Micah Lott, claims that the neo-Aristotelian concept of a living organism has to be presupposed in evolutionary biology as long as organisms are the subjects of evolutionary explanation. In this paper, I examine this response by tracing the concept of organism in modern evolutionary biology. I first argue that the Modern Synthesis theory of evolution, which understands evolution as change in gene frequencies within a population, does not presuppose the relevant concept of organism. I then explore an alternative view of evolution that has emerged in the past twenty years from advances in evolutionary developmental biology. I argue that this so called ‘evo-devo’ approach makes room for an explanatory concept of organism that can be reconciled with the neo-Aristotelian view. Moreover, I argue that although the explanatory role of the concept of organism in evolutionary biology is still contentious, the well-established role of this concept in developmental biology can be used to defend the biological commitments of neo-Aristotelian naturalism.