Open inquiry and engagement with a diverse range of views are long-cherished and central tenets of higher education and are pivotal to innovation and knowledge creation. Yet, free inquiry on American campuses is hampered by a climate that constrains teaching, research, and overall discourse. In Unassailable Ideas, Ilana Redstone and John Villasenor examine the dominant belief system on American campuses, its uncompromising enforcement through social media, and the consequences for higher education. They argue that two trends in particular—the emergent role of social media in limiting academic research and knowledge discovery and a campus culture increasingly intolerant to diverse views and open inquiry—are fundamentally reshaping higher education. Redstone and Villasenor further identify and explain how three well-intentioned unwritten rules regarding identity define the current campus climate. They present myriad case studies illustrating the resulting impact on education, knowledge creation-and, increasingly the world beyond campus. They also provide a set of recommendations to build a new campus climate that would be more tolerant toward diverse perspectives and open inquiry. An insightful analysis of the current state of academia, Unassailable Ideas highlights an environment in higher education that forecloses entire lines of research, entire discussions, and entire ways of conducting classroom teaching.