With the Supreme Court’s prohibition of race-conscious affirmative action and the Trump administration’s efforts to end diversity, equity, and inclusion programs, universities and law schools have been rethinking academic, student, and related programs. As we think through the issues, we have a new resource, law professor David Oppenheimer (UC Berkeley)’s very timely book, The Diversity Principle: The Story of a Transformative Idea by David B. Oppenheimer (Yale University Press, 2025).

David B. Oppenheimer’s The Diversity Principle traces one big claim across two centuries, that mixed groups of people think and act better than homogenous ones. He follows this idea from Wilhelm von Humboldt’s experiments with the early research university, through John and Harriet Mill’s defense of diverse voices in public life, into Charles Eliot’s reinvention of Harvard, and then through the long legal fight over academic freedom and affirmative action in the United States. Along the way, he folds in South Africa’s “open universities,” the growth of “diversity science,” the corporate “business case for diversity,” and finally the recent Supreme Court rejection of race-conscious admissions and the wider political backlash against DEI work.