His research spans a number of areas in ethics. Recent work includes his book, Moral Heroism without Virtue (Cambridge University Press, 2025), which argues that virtue-theoretic approaches to moral heroism misunderstand its significance, and then develops an account of moral heroism – without virtue. Continuing work includes a monograph on sportswashing, as well as papers in climate ethics.

His teaching interests at Duke Kunshan include places where ethical questions intersect with other parts of the curriculum, like global challenges and environmental ethics. He serves as the Common Core Coordinator, and is the Chair of the Duke Kunshan University Institutional Review Board (DKU IRB).

Fruh holds a B.A. in philosophy and Spanish from Amherst College, an M.A. in philosophy from the University of Colorado, Boulder, and a Ph.D. in philosophy from Georgetown University. Before joining Duke Kunshan, he was a visiting assistant professor at Beloit College and a Thinking Matters postdoctoral fellow at Stanford University.