Welcome! I'm a philosophy professor at Colorado State University in Fort Collins, Colorado. My scholarly work centers on ethics, particularly environmental ethics and virtue ethics, and their intersection specifying a positive vision for people flourishing within nature, rather than overwhelming it. I'm the author of Thoreau's Living Ethics: Walden and the Pursuit of Virtue and How Many Is Too Many? The Progressive Argument for Reducing Immigration into the United States. I am an affiliated faculty member of CSU’s School of Global Environmental Sustainability and past president of the International Society for Environmental Ethics. I live in Fort Collins with my wife Kris and sons Henry and Tom.

For the past two years, Swedish ecologist Frank Gotmark and I have been co-principle investigators on a new effort, The Overpopulation Project, headquartered at the University of Gothenburg, Sweden. With help from a generous grant from the Global Challenges Foundation, we have been studying the environmental impacts of overpopulation and exploring humane policies to end population growth around the world. Initial publications include Aging Human Populations: Good for Us, Good for the Earth” in Trends in Ecology and Evolution, and Policy-based Population Projections for the European Union: A Complementary Approach” in Comparative Population Studies. TOP's most popular blog has been "Solutions to overpopulation and what you can do."