Guru Nanak occupies a unique place amongst the spiritual leaders, reformers and saints of India. His teachings have a universal appeal and they hold good for all ages. He was a great thinker, a wonderful mystic, and a distinguished social reformer. He was a revolutionary prophet, a litterateur of high calibre and a person of extraordinary foresight. In addition to all this, Guru Nanak was a prophet with a scientific attitude. In this article, Guru Nanak's anti-dogmatic outlook and his attitude (...) of questioning the established irrational beliefs, superstitions and illogical traditions are described, taking instances from his hymns and his life events. (shrink)