By the early twenty-first century, a phenomenon that once was inconceivable had become nearly commonplace in American society: the public spiritual teacher who neither belongs to, nor is authorized by a major religious tradition. From the Oprah Winfrey-endorsed Eckhart Tolle to figures like Gangaji and Adhyashanti, there are now countless spiritual teachers who claim and teach variants of instant or immediate enlightenment. American Gurus tells...