The journey of a spiritual aspirant through contemplation is a direct and difficult path. The risis of yore have elaborated and elucidated this teaching, particularly in the Chandogya Upanishad, of the Upadesa Mahavakya Tattvamas i-That Thou Art. Bhagvan Adi Sankaracarya, in his utter compassion, benevolence and unique versatility, being forth a prakarana text in verse form for the sadhakas, of the highest teaching enshrined in this thought provoking statement with its word meaning (vacyartha) and its import (laksyartha) and the consequnt dawning of Aham Brahmasmi in the sadhaka' s mind. Swami Chinmayananda in this commentary makes a very lucid and deep analysis of the intricate and subtle thought development of the sentence 'That Thou Art'. He brings out clarity into how to understand each word of the statement and arrive at the clear meaning of the Mahavakya for us all in this beautiful dialogue between teacher and student. A great aid and blessing to all serious sadhakas on this very subjective analysis of self - enquiry.