 In the Sikh tradition, the themes of Nanak's poetry are very broadly similar to the "Nirgun bhakti" ideas of Ravidas and other leading north Indian saint-poets.Most postmodern scholars, states Karen Pechilis, consider Ravidas's ideas to belong to the "Nirguna" philosophy within the bhakti movement.Multiple manuscripts found in Rajasthan and Uttar Pradesh, dated to be from the 18th and 19th centuries, contain a theosophical debate between Kabir and Ravidas on the nature of the Absolute, more specifically whether the Brahman (Ultimate Reality, Eternal Truth) is monistic Oneness or a separate anthropomorphic incarnate.