MANDUKYA, though it is the smallest UPANISD  - it consists of only twelve short passages - it encompasses the entire range of human consciousness. It describes beautifully all the states of consciousness along with the discipline - Sadhna to raise our consciousness from the lowest to the highest, culminating in full attainment of the Self-Atman or Brahman.

The main subject discussed in the Prasna Upnisad that of Prasna (The Primal Energy) in the form of four questions. The fifth question is about Pranava. In it we get the indication about the Sadhana spiritual discipline to realise the ultimate Truth. The last question is about the Goal, about the Being whom we have to discover in ourselves.

Shri Anirvan was born on July 8,1896 in the town of Mymensingh (now in Bangladesh). At the age of eleven he knew the Astadhyayi of Panani by heart and daily recited a chapter from the Gita. He went for his college studies to Dhaka and later on to Calcutta. After completing his studies, Shri Anirvan took Sanyasa and became Nirvanananda Saraswati. But a few years later he dropped the ochre robes and changed his name to Anirvan, by which name he became known to the world at large.

Between 1983 and 1942, he lived with a friend at Allahabad, Lucknow, Delhi and Ranchi. Later on, he moved to Lohaghat in Almora where Madame Lizelle Reymond, a Swiss lady, Spiritual seeker joined him and literally took him to the West through her books. Shri Anirvan moved to Shillong in Assam and finally to Calcuta in 1965. He fell ill in July 1971 and passed away on 31 May, 1978 at the age of 82.

His first book was a Bengali translation of Shri Aurobindo's The Life Divine which was published in 2 vols. during 1948-51. But the centre of his studies was the Vedas on which subject he acquired a rare mastery over the years. His great work, Veda Mimamsa, in Bengali was published in 3 vols. in 1961, 1965 and 1970. Meanwhile, several other works on Upanishads, the Gita, Vedanta and Yoga had also been published in Bengali and translated into English and Hindi.