Book excerpt: Building sustainable diversity in higher education isn't just the right thing to do—it is an imperative for institutional excellence and for a pluralistic society that works. In Diversity's Promise for Higher Education, author Daryl G. Smith proposes clear and realistic practices to help institutions identify diversity as a strategic imperative for excellence and pursue diversity efforts that are inclusive of the varied issues on campuses—without losing focus on the critical unfinished business of the past. To become more relevant while remaining true to their core missions, colleges and universities must continue to frame diversity as central to institutional excellence. Smith suggests that seeing diversity as an imperative for an institution's mission, and not just as a value, is the necessary lever for real institutional change. Furthermore, achieving excellence in a diverse society requires increasing institutional capacity for diversity—working to understand how diversity is tied to better leadership, positive change, research in virtually every field, student success, accountability, and more equitable hiring practices. In this edition, Smith emphasizes a transdisciplinary approach to the topic of diversity. Drawing on fifty years of diversity studies, this fourth edition engages with how the environment has transformed for diversity work since the third edition appeared in 2020. It • addresses the changed landscape in which DEI work has been politicized both on and off campus; • provides examples and language to suggest ways to articulate the centrality of diversity to mission and excellence; • emphasizes the link between healthy democracies and higher education's mission in light of the current global and domestic challenges to democracy; • highlights the need to focus on the conditions for developing healthy communities where dialogue, difference, and learning can take place; • examines the current climate of campus protests and the implications for free speech and academic freedom; and • reemphasizes the complexity of identity—and explains how to attend to the growing kinds of identities relevant to diversity, equity, and inclusion while not overshadowing the unfinished business of race, class, and gender.