John Kaag is an American philosopher, writer, and public intellectual whose work bridges academic philosophy, memoir, and American intellectual history. He is Professor and Chair of Philosophy at the University of Massachusetts Lowell and an External Professor at the Santa Fe Institute, where he previously held a Miller Scholarship from 2019 to 2021.

Trained as a historian of American philosophy, Kaag writes on topics ranging from the philosophy of education and imagination to the ethics of contemporary warfare and the existential stakes of everyday life. His early scholarly work includes Idealism, Pragmatism, and Feminism: The Philosophy of Ella Lyman Cabot (2011) and Thinking Through the Imagination: Aesthetics in Human Cognition (2014), which explores the role of imagination in human thinking. He has also written on the moral challenges of new technologies in Drone Warfare (2016).

Kaag is best known to a broad readership for philosophical memoirs and literary works that use narrative to make complex ideas emotionally and intellectually accessible. American Philosophy: A Love Story (2016) received the John Dewey Prize from the Society for U.S. Intellectual History, was named an NPR Best Book of 2016, and was a New York Times Editors’ Choice. Its “dark sequel,” Hiking with Nietzsche: On Becoming Who You Are (2018), was also singled out by NPR and the New York Times. He has continued his engagement with the American tradition through books on William James—Sick Souls, Healthy Minds: How William James Can Save Your Life (2020) and Be Not Afraid of Life: In the Words of William James (2023)—and on Henry David Thoreau in Henry at Work: Thoreau on Making a Living (2023).

His recent work, including American Bloods: The Untamed Dynasty That Shaped a Nation (2024) and Thinking Through Writing: A Guide to Becoming a Better Writer and Thinker, turns from the therapy of the individual soul to questions about the “soul of a nation” and the practices of reading and writing that sustain philosophical reflection. Kaag also writes for The Paris Review, The New York Times, and Harper’s Magazine.