A) The Bhagavad Gita
The Bhagavad Gita (the "Song of God") is set up as a dialogue between prince Arjuna, son of King Pandu, and Lord Krishna, who served as Arjuna's guide and chariot driver. The poetic scriptures focus extensively on the Hindu concept of dharma, which is a hard word to translate into English without using multiple words. But "duty" is a key ingredient in the overall emphases of dharma. Dharma points to behaviors that are in accordance with law and virtue, and pays respect for principles that promote a good and right way of life.
