This volume comprises Sri Aurobindo's translations of and commentaries on Upanishads other than the Isha Upanishad. (His writings on that Upanishad appear in Isha Upanishad, volume 17 of THE COMPLETE WORKS OF SRI AUROBINDO.) It also includes his translations of later Vedantic texts and writings on the Upanishads and Vedanta philosophy in general.

The volume is divided into three parts. The first consists of translations and commentaries that were published during Sri Aurobindo's lifetime. The pieces in this part, along with his final translation of and commentary on the Isha Upanishad, are his most mature works of Upanishadic interpretation. The second and third parts consist of material from Sri Aurobindo's manuscripts. The second includes early translations of the Prashna, Mandukya, Aitareya and Taittiriya Upanishads, and incomplete translations of and commentaries on some other Upanishads and Vedantic texts. The third part comprises incomplete and fragmentary writings on the Upanishads and Vedanta in general.

All the texts have been checked against the relevant manuscript and printed versions.

Guide to Editorial Notation

The contents of Parts Two and Three of this volume were never prepared by Sri Aurobindo for publication. They have been transcribed from manuscripts that sometimes present textual difficulties. In this edition these problems have been indicated as far as possible by means of the notation shown below.

Notation	Textual Problem
[.......]	Word(s) lost through damage to the manuscript (at the beginning of a piece, sometimes indicates that a page or pages of the manuscript have been lost)
[word]	Word(s) omitted by the author or lost through damage to the manuscript that are required by grammar or sense, and that could be supplied by the editors
[ ]	Blank left by the author to be filled in later but left unfilled, which the editors were not able to fill
[note]	Situations requiring textual explication; all such information is printed in italics