I was very hungry for meditation teachings in the late '60's and early '70's but satisfying meditation teachings were hard to come by. I wolfed down Evan Wentz's translation of a Dzog Chen text (The Tibetan Book of the Great Liberation: Or the Method of Realizing Nirv=ana through Knowing the Mind) and really wanted to find a flesh and blood teacher, since anything I could read on the subject said a flesh and blood teacher was essential. I tried Zen but it didn't "click" for me. I read the early editions of Crystal Mirror ( Footsteps on the Diamond Path Crystal Mirror 1 - 3) ) which were published by Tarthang Tulku as well, and some of the translated meditation texts in there really resonated with me.Based on flyers posted at the Bodhi Tree Bookstore in Los Angeles, I ended up going to 4 or 5 weekend seminars, in 1971, at the Tibetan Nyingma Meditation Center in Berkeley, California, as given by Tarthang Tulku, the writer/transmitter/editor of this book. Those seminars blew my mind (in a good way, not in a Day in the Life way) and I moved up to Berkeley and studied at the center for a year, at a time when Tarthang Tulku was more accessible to run of the mill, off-the-street, students.During those two years - the year at home digesting the weekend seminars, and the year at the Center working/practicing - Dzog Chen was never taught. Formally. All of us gossiped and buzzed about it, but empowerments and instructions were not forthcoming. (We did have a meditation class, we did have simple body movements and postures to practice but these were never formally associated with Dzog Chen). Since we were told to work gung-ho at Dharma Press or on various other projects at the Center, while doing simple prostration practice (often not even the more formal Ngondro curriculum which is very widespread these days) as our core practice when we got home late at night, it got disheartening after a while and I left, tail between my legs.Meanwhile Tarthang Tulku, Rinpoche, was writing this book. Actually writing is a misnomer, he had a brilliant student that he would sit down with and dictate/discuss the passages with. Tarthang Tulku was an amazingly adept communicator, charismatic, and had a way of filling tons of meaning into very simple, "beginner's English" (he was learning English on the fly, and teaching his students Tibetan). It was the student's job to "translate" Tarthang Tulku's discourses into the heart of the book. Tarthang Tulku was a stickler for detail, and would ask the student to read what he wrote, they would discuss it and hammer out the meaning. So essentially what you are reading is not Tarthang Tulku hammering out words at a typewriter to be edited, it is a mash-up of dictated to, edited by BOTH sides, translation/rephrasing, and collaboration. I heard many, many dharma discourses by Tarthang Tulku during my time at the Center, and while Tarthang Tulku never spoke like he does in this book (he had "broken" English at the time) or wrote like this book, the book is CLEARLY a product of his mind, and the concepts and principles and turns of phrase echo and reinforce everything he was teaching us at the time. I think in many ways his residential group of students also served as a testing "lab" for much of what ultimately went into this book.Even as I read this over 30 years later, it brings back clear images and poignant memories.At the time, when this book came out, many of us had a "WTF??" reaction because Tarthang Tulku was a "traditionalist," interested in the preserving Buddhist texts (he reprinted the entire library of Nyingma tantras), not like that "wild" teacher Chogyam Trungpa who seemed to be "repackaging" the Dharma into modern language and concepts. And then Time Space Knowledge came out and we wondered who really was the traditional teacher and who was the wild cowboy!There are a few Buddhist and Bon teachers who teach Dzogchen publicly or semi-publicly today. Some require fulfillment of the precursor practices (Ngondro) which is daunting and extremely time-demanding. Others teach Dzogchen more freely or with a Dzogchen Ngondro.But if you find the complexity of the path too daunting/not interesting/in conflict with your religion, this book is an absolute gold mine. The claim of Dzog Chen is that it is not limited or "owned" by the religious tradition that is Buddhism (although Buddhism, in general, is an excellent preparation), but there are few authentic texts of "secular" Dzog Chen. In fact, I would venture that this book, and its follow-ups, are the only secular exposition of Dzog Chen.Although Tarthang Tulku's students are a rather private group, I have talked to a few and even within the community there is division on whether TSK is "disguised Dzog Chen" or not. Or what role it plays in the Dharma (Buddhist religion).My conclusions, 39 years later are as follows:1. Tarthang Tulku talks of his Time/Space/Knowledge "vision." I equate this with the terma revelations of more traditional liturgical practices within the Nyingma tradition. (Look up "terma" on Wikipedia if you are insatiably curious!). Tarthang Tulku has never, to my knowledge, called this book a "terma" but I believe,imho, that it is the equal of any terma (the Great Liberation text translated by Evans Wentz and cited above is a "terma").2. Yes, TSK is serving up Dzog Chen views and practices without the chanting, robes, offering bowls or other Buddhist practices. TSK REALLY cuts things to the bone!If you really don't like to get involved with groups, there is probably no better place to start a DIY (do it yourself) program than with this book and with the Kum Nye movement/meditation practices laid out here Kum Nye Tibetan Yoga: A Complete Guide to Health and Wellbeing .I have read some of the follow up books in the TSK series and none are as ground breaking as this one, so start here first if you are interested....