MANY PEOPLE HAVE contributed to this book. To start with, I would like to thank Udayan Mitra for encouraging me to write this, Ranjana Sengupta, Aditya Mani Jha and Shreya Chakravertty for improving the text through their suggestions and expert editing, and all others at Penguin Random House India involved in the book’s production and design.
I would also like to thank the several friends with whom I have discussed these texts over the years, and who contributed to my understanding of them.
Finally, I would like to express my deep appreciation of those rishis, yogis and sannyasis who composed and commented on the Upanishads, and to those who continue to share their insights into these profound texts.