J. Baird Callicott is University Distinguished Research Professor Emeritus and Regents Professor of Philosophy, ret. at the University of North Texas. He taught the world’s first course in environmental ethics at the University of Wisconsin-Stevens Point in 1971. Callicott is co-Editor-in-Chief of the Encyclopedia of Environmental Ethics and Philosophy and author or editor of many books and author of dozens of journal articles, encyclopedia articles, and book chapters in environmental philosophy and ethics. His writings have been translated into French, Spanish, German, Russian, Japanese, and Chinese. Callicott has served the UNT Department of Philosophy as chair, the International Society for Environmental Ethics as President, and Yale University as Bioethicist-in-Residence. He is a leading contemporary exponent of Aldo Leopold’s land ethic and has elaborated an Earth ethic, Thinking Like a Planet (Oxford University Press 2013), in response to climate change. Most recently, he returned to his roots in classical scholarship with Greek Natural Philosophy: The Presocratics and their Importance for Environmental Philosophy (Cognella 2018).