 The traditions of the Naiyāyikas and the Vaiśeṣikas strongly disagreed with the views of the Mīmāṃsakas and they developed their own distinctive conceptions of language, meaning, and scriptural authority. They agreed with the Mīmāṃsakas that the Vedas were a source of authoritative knowledge (śabda-pramāṇa), and yet they offered a different set of reasons. According to them, only the words of a trustworthy speaker (āpta) are a source of authoritative knowledge. They joined the Mīmāṃsakas in arguing that no humans, including Buddha and Mahāvīra, are free from ignorance, passion, etc., and no humans are omniscient, and therefore the words of no human being could be accepted as infallible. However, they did not agree with the Mīmāṃsakas in their rejection of the notion of God. In the metaphysics of the Nyāya-Vaiśeṣika tradition, the notion of God plays a central role. In defending the notion of God (as in the Nyāyakusumāñjali of Udayana), they claimed that God was the only being in the universe that was omniscient and free from the faults of ignorance and malice. He was a compassionate being. Therefore, only the words of God could be infallible, and therefore be trusted. For the Naiyāyikas and Vaiśeṣikas, the Vedas were words of God, and not the words of human sages about God. The human sages only received the words of God in their meditative trances, but they had no authorship role.