While the activity of sacrifice is still presumed in the period of composition of the Upaniṣadic texts, the object of sacrificial knowledge is no longer the actual procedures of the sacrifice or the gods per se but a new force called brahman. Brahman is thought of as the power behind the sacrifice, and as the Upaniṣadic thought developed, it was described as the power behind every living thing and every element in the universe. Brahman is "the Whole" (Bṛhadāraṇyaka Upaniṣad 2:5) and transcends even the gods. It also exists beyond all known things in this world, and yet is also present within them as well. It is set apart from beings and yet dwelling within beings at the same time. This basic identification between the selves of beings and brahman leads to the famous Upaniṣadic equation that the self (ātman) is the same as the power behind the universe (brahman). As the sage Yājn̄avalkya puts it, "The self within all is this self of yours." The larger brahman is also spoken of as the ātman or "self" of the universe, thus giving rise to the poetic nineteenth-century translation "the World-Soul." The earliest Upaniṣads probably originated around 600 to 500 bce and were composed in prose. They shared a common focus on many topics, such as the nature of brahman, the nature of sacrificial speech and the verses, the various forms of breath, and the homologization of parts of the body to the powers in the universe. The teaching of the five fires as the essence of the major parts of the cosmos (e.g., fire as man, woman, and the three worlds) is especially distinctive in these early prose compositions. The later Upaniṣads are composed in verse and develop the theme of brahman into a theistic rather than monistic conception. They also focus on the idea of liberation through meditation. Both are themes common in later Purāṇic cosmologies.