In book four Lord Krishna describes a refinement of Cosmic Consciousness in which the perception of the relative states of consciousness is cultured to reveal the underlying celestial quality of life. Krishna shows this state to Arjuna when He describes their previous incarnations in verse five, saying "I know them all but you know them not." This portrayal of all-knowingness by the Lord begins to reveal His divine character to Arjuna,

In this book Lord Krishna also describes various means of self-purification for development of higher states of consciousness culminating in realization of the Self gained in meditation, the highest form of purification.