Mandukya Upanisad (with commentary of Sankaracarya)
Swami Gambhirananda
The unique feature of this Upanishad lies in this that while all the other Upanishads deal with several phases of Vedanta, such as Religion, Theology, Scholasticism, Mysticism, Metaphysics and Philosophy, this one deals exclusively with Philosophy, as defined by the most modern authorities. It deals with the three fundamental problems of Philosophy, viz. the nature of external and internal worlds, the nature of consciousness, and the meaning of causality. In short, it contains the quintessence of all the Upanishads. Here the reader finds the highest Truth conveyed in a most explicit and an uncompromising manner. The book contains the Upanishad along with Gaudapada's Karika. The book contains a lucid english translation of the text along with Shankaracharya's commentary on it.
Those who grumble at the little thing that has fallen to their lot to do will grumble at everything. Always grumbling, they will lead a miserable life, and everything will be a failure. But those who do their duties as they go, putting their shoulders to the wheel, will see the light, and higher duties will fall to their share.
-Swami Vivekananda