Date of Award

Winter 12-15-2014

Author's School

Graduate School of Arts and Sciences

Author's Department


Degree Name

Doctor of Philosophy (PhD)

Degree Type




Bio-Enhanced Constructivism: Moral Facts for the Naturalistic but Morally Serious Philosopher


Jason Gardner

Doctor of Philosophy in Philosophy

Washington University in St. Louis, 2014

Professor Eric Brown, Chair

There is a tension between being both morally and naturalistically serious because it is doubtful that features philosophers have ascribed to moral facts in order to explain why we should take them seriously can be given a naturalistic accounting. Yet even serious naturalists who think the tension is real and troubling persist in trying to be serious moralists. I do not think they can do so on their own terms. Thus the purpose of this dissertation: to inquire after a perfectly natural way to think about morality, one that begins by examining the colloquially moral behaviors of the natural human animal, one that also demands that we take morality seriously. I call the view that emerges 'Bio-Enhanced Constructivism'. It consists of two theses: the Human Nature Thesis saying it belongs to the human species to have peculiarly moral desires, and the Biological Construction Claim saying moral facts are determined by certain evaluations that these desires dispose us to make. I defend the view in three steps. First I present evidence from the biological and psychological sciences for the Human Nature Thesis. Then I argue that the Biological Construction Claim is the only viable way to make sense of how there could moral facts determined by our evaluations. Finally, I consider a great number of objections claiming to undermine the justification a bio-enhanced constructivist offers for our taking morality seriously and I show that none of these objections is able to uphold its claim.


English (en)

Chair and Committee

Eric Brown

Committee Members

Carl Craver, John Doris, Julia Driver, Joan Strassman


Permanent URL:

Included in

Philosophy Commons