Bhagavad Gita: A dialogue between Arjuna and Krishna, this text explores themes of duty, action, and devotion. It integrates Samkhya thought with theistic schools and Vedanta.
Not only seen it but read quite a bit of it back in college SO long ago. A course that included large parts of the BHAGAVAD GITA, UPANISHADS, SILAPPADIKARAM, and some other texts I don't recall. After 50+ years I might still have them out on the bookshelves in the garage.
