I Am That is a compilation of talks on Shiva Advaita (Nondualism) philosophy by Sri Nisargadatta Maharaj, a Hindu spiritual teacher who lived in Mumbai. The book is considered the author's masterpiece and a spiritual classic by authors and teachers like Eckhart Tolle,Wayne Dyer, Deepak Chopra. Main themes discussed in the book :identification with the body, meditation on the "I am" Feeling, surrender to the Truth, conceptual knowledge and earnestness.