One of Deloria's most controversial books, The Metaphysics of Modern Existence emphasizes that Native Americans have consistently perceived their realities experientially, confronting the reality of the experience, whereas Westerners often hold academic learning and theories above experience. This difference in perception and thought has had and continues to have very real environmental and political ramifications, not to mention personal and social consequences. Deloria's Metaphysics adroitly answers the often unasked question: what does an Indian think about the modern world.