Ashrams in Europe twenty-five hundred years ago? Greek philosophers studying in India? Meditation classes in ancient Rome? It sounds unbelievable, but it's historically true. Alexander the Great had an Indian guru. Pythagoras, Empedocles, and Plotinus all encouraged their students to meditate. Apollonius, the most famous Western sage of the first century c.e., visited both India and Egypt--and claimed that Egyptian wisdom was rooted in India. In...