In 1955, the Arya text of the Introduction, the 1948 text of Part I, a text of Part II incorporating Sri Aurobindo’s revisions from Period 2, and the Arya texts of the chapters comprising Part III and Part IV, were published by the Sri Aurobindo International University Centre as On Yoga I: The Synthesis of Yoga. (On Yoga 11, published in 1958, consisted of a selection of Sri Aurobindo’s letters on yoga.) The in¬ complete chapter “The Supermind and the Yoga of Works” appeared in this edition for the first time as chapter XIII of Part 1. The SAIUC edition was reprinted, with corrections, in 1957. The same publisher (under the new name Sri Aurobindo International Centre of Education) issued a new edition of the same text in 1965.
In 1970 The Synthesis of Yoga was published as volumes 20 and 21 of the Sri Aurobindo Birth Centenary Library. This edition was reprinted many times.
The present edition has been thoroughly checked against all re¬ lated manuscripts and printed texts. Many typographical and other errors have been corrected. The edition includes for the first time Sri Aurobindo’s scattered revisions in the Introduction and substantial revision of chapters XV -XVII of Part II. It is the first edition of the book to include the text of “The Supramental Time Consciousness”, the incomplete chapter Sri Aurobindo wrote for Part IV before setting aside “The Yoga of Self-Perfection”.