Guru Nanak (1469-1539) promulgated a unique and universal philosophy of humanism in the Indian sub-continent as the renaissance was taking place in Europe (14th to 16th centuries) and scientists were challenging illogical religious concepts and beliefs. Guru Nanak carried his message far and wide to South Asia and the Middle East. He held discussions with religious leaders: Hindus—(Brahmans, Sidhs and Jogis), Muslims—(Sufis, mullahs and Qazis), Jains and Buddhists in India, the Middle East, Tibet and Ceylon (Sri Lanka).