...One must realise that dzogchen was developed in a certainculture therefore much is taken for granted in dzogchen works. Oneonly has to look at the four gospels, words that according to Jesus himself are extrinsic to the teachings to his disciples and note the ramified results of that: materialism in a dying world. Herbert Guenther's ramifications of the implications of dzogchen driven through the western mind set are some of the most valuable dzogchen works these days. In the twenties there was the discovery of quantum physics, that really upset the establishment apple cart, it went forward too fast to be suppressed, however they have managed to limit quantum physics to the subatomic level, thus allowing the civilisation to be frozen in accord with their desires to retain power and position. Translations of tibetan works that remain in a taken for granted mindset already commodified in the west maybe ok for lotus eaters, but won't have much impact.
Many say Geunther is a genius. I might agree. He has some extraordinary, unique perspectives, apparently born from many years of study, in both Tibetan as well as European philosophies. But a translator? It seems he fancies himself more a sort of "decoder," if you will, and his (sometimes lengthy) reasonings behind his peculiar, intense word choices often appear sound. Yet as the years go on, and students of this genre grow in there understanding of key terms, key-term translation is becoming more-and-more standardized, leaving his "translations" less-and-less accessible.
If you work at it, you can squeeze out many of the original Tibetan terms from his indexes, footnotes, etc., and thereby triangulate with the more commonly-used terms. -Somewhat tiresome if what you really want is a more direct translation, for use in a student-teacher situation for example. Furthermore, this book and the other two in the trilogy are much more commentary than translation. This is a shame, since Longchenpa himself wrote an auto-commentary to them.
That said, Guenther IS a great thinker, and if you would like to read Guenther, as opposed (in this case) to Longchenpa, then I'll say, this and all of the books I've read by him (some dozen) are truly fascinating. Very original and thought-provoking.
Maybe look for a translation elsewhere. -no offense, Herb.