Hinduism is believed to be one of the oldest living religions on Earth, with origins tracing back to the ancient Vedic civilization in India. Of all Vedic literature, the Upanishads alone are widely known, and their central ideas are at the spiritual core of Hinduism. The teachings were imparted in the form of dialogue between teacher and disciple. These ennobling lessons are practical for the modern world. Their teachings are summed up in two great sayings: Tat twam asi (That thou art) and Aham Brahmasmi (I am Brahman). This oneness of Soul and God lies at the very root of all Vedic thought, and the dominant ideal points to the unity of all life and the oneness of Truth.