Philosophy Ph.D. Dissertations


Against Natural Teleology and its Application in Ethical Theory

Date of Award


Document Type


Degree Name

Doctor of Philosophy (Ph.D.)


Philosophy, Applied

First Advisor

Daniel Jacobson, PhD (Committee Chair)

Second Advisor

William Mathis, PhD (Committee Member)

Third Advisor

Michael Bradie, PhD (Committee Member)

Fourth Advisor

Christian Coons, PhD (Committee Member)

Fifth Advisor

John Basl, PhD (Committee Member)


Many ethical theories depend on the existence of natural teleology as a source of normativity. Natural Teleology, the purposive goal-directedness of non-conscious biological processes, is also embraced to some degree by a majority of philosophers of biology who agree that the teleological concepts of purpose, goal, defect, proper function and malfunction are legitimate, perhaps necessary, in biological explanations. In my dissertation I provide a substantive argument against the reduction of teleology to natural facts and argue that ethical theories that rely on it cannot be naturalistic. Several ethical theories could be my target, but I focus on the most overt example: neo-Aristotelian ethics. The project is in two sections, one in ethical theory and the other in philosophy of biology. In the first section of the dissertation, primarily using Philippa Foot and Judith Jarvis Thomson as models, I illustrate how Neo-Aristotelian theories rest on natural teleology. I offer a metaethical analysis of teleology, arguing that it does not belong to the good nor the right nor mere description, but rather the proper. I call this category of concept protonormativity. I claim that protonormativity, of which teleology is a paradigmatic example, does not yield normative facts and is not reducible to natural facts; it is a distinct conceptual category. In the second section I give a novel argument for why natural teleology cannot be reduced to natural facts. Teleological concepts such as design and proper function imply standards of correctness for phenotypic outcome. They entail norms for the way an item is to be in the end: functional or malfunctional, good or defective. However, since a phenotype is the result of a genotype in some set of environmental conditions, there can only be a proper phenotype if there exists a proper environment for the item to inhabit. Regarding artifacts, a designer is capable of setting a proper environment, but I argue science does not admit of proper environments for organisms in nature. The concept proper environment cannot be reduced to any set of natural facts. Therefore metaethical naturalists must abandon proper phenotypes, natural teleology, and ethical theories that rely on it.