The Bhagavad Gita and the Prasna Upanishad are the closest examples in the “Eastern Canon” to a dialectical dialogue, such as a Platonic dialogue.
In the Prasna Upanishad, we encounter six students full of devotion to Brahman, “the Supreme Spirit.” In their quest for the highest Brahman they approach the holy Pippalada to explain the sacred teaching. However, he tells them to wait one year, and then he will answer each question.
Kabandhi Katyayana asks “whence came all created beings?”
The sage responds with a myth. He says, in the beginning the creator longed for the “joy” of creation through Rayi (matter) and Prana (life). This differentiation became day and night, and the sage also states that those who follow and obey the law of the Lord of Creation become creators, like the pale side of the moon, however those who live without deceit or purity live like the radiant sun. He quotes the Rigveda.
Bhargava Vaidarbhi asks: what are the powers that keep the union of being, how many keep burning the lamps of life, and which is supreme? -an ontological question.
The sage says the powers are space, air, earth, water, and fire; and voice, mind, eye, and ear. Together these keep the foundation of being, however, life, like the queen bee, is the supreme ruler. The second half is a prayer of praise dedicated to life.
Kausalya Asvalayana asks whence does life arise? How does it come to this body? How does it abide and leave? How does it sustain the universe within and without?
The sage states that life comes from the spirit, like a long shadow. The Atman is the inner self that lives in the heart. One attains life everlasting by knowing the meaning of life. This is the only student praised for his pursuit of Brahman by the sage.
Sauryayani Gargya asks how many powers remain awake in man? Who is the spirit that beholds dreams? Who has no dreams? Who is the spirit on whom all others find rest?
Like a setting sun, the spirit sleeps, but not the body (notice the early distinction between mind/body). In dreams the mind “beholds its own immensity.”Peace comes to those who draw inward to their highest Atman.
Saibya Satyakama asks: what happens to the man who rests his life on om after death?
He who who rests on the three sacred sounds travels beyond and finds peace without death. He finds these harmonies in the Rigveda, Yajurveda, and Samaveda.
Sukesa Bharadvaja asks about a prince who once asked if he knew the Spirit sixteen forms. Upon response, the student says he does not know him and he speaks not untruth.
The Spirit rests in the body. It disappears beyond oceans and rivers. The students praise the sage and seers, as the sage tells them that he knows the Supreme Spirit and that there is nothing beyond.
For this reading I used the Penguin Classics Edition translated by Juan Mascaro.