Yoshiteru Hayashi is a Post Doctoral Researcher at the Faculty of Letters and Arts, Tohoku University, Japan. He got his Ph.D. from Tohoku University in 2005. He studies ancient Indian religious thought. His main interest is in the emergence and the development of the concepts in Indian religious thought, such as theory of karma, reincarnation. During his stay at the Harvard-Yenching Institute, his research focused on the Brhadāranyaka-Upanishad, one of the earliest Upanishads.