The Samdhinirmocana is surely one of the most important Mahayana Buddhist texts. Being possibly the first and most influential of the “third turning” texts of the Yogacara school, it ushers in new concepts like the three natures and the alayavijñana which became key concepts of later thinkers like Asanga and Vasubandhu. For a modern English speaking Buddhist who wants to get an understanding of the Mahayana, no other sutra save the Prajñaparamita is as important as the Samdhinirmocana. Sadly, it is not as widely read or known.
There are currently 3 English translations of this work, Powers (1995), Keenan (2000) and Cleary (1995). The Cleary is out of print as far as I know. The main choices are really between the Powers and Keenan.
The Powers is translated from the Tibetan, Keenan from the Chinese of Xuangzang. Besides the source difference, my reading of the texts noticed that the Powers seems a less detailed translation than the Keenan. Tom Tillemans in his review of Powers - “On a Recent Translation of the Samdhinirmocanasutra” notes this as well. Tillemans does not mince words: “the translation is often quite unreliable, having errors which seriously obscure the basic sense of the sutra’s words”. Tillemans examines various passages which are useful in giving a sense of the difference in translations.
Chapter I (Powers p. 12-13f.)
Tillemans notes that Powers missed the fact that there is an actual objection here that can best be rendered as “But words must have objects, so what is the object here?" – Powers misses this. Tillemans also notes:"Son of good lineage, 'uncompounded' is also included within the conventional. Even if something were expressed that is not included within the compounded or uncompounded it would be just the same as this. It would be just like this. An expression is also not without thingness. What is a thing? It is that to which the Āryas completely and perfectly awaken without explanation, through their exalted wisdom and exalted vision. Because they have completely and perfectly realized that very reality which is inexpressible, they designate the name 'compounded'.
...
"It is that to which the Aryas completely and perfectly awaken without explanation, through their exalted wisdom and exalted vision. Because they have completely and perfectly realized that very reality which is inexpressible, they designate the name 'compounded’”
Now let’s see how Keenan (Keenan, p. 12) renders this same passage, translating from the Chinese:Powers, in effect, should have read a dative for the Tibetan .. . de nyid mngon par rdzogs par rtogs par bya bdi phyir, i. e., "in order that [others] might perfectly understand reality," rather than an ablative "because they [i. e. the Aryas] understand...."
Here is the Cleary (p.5) as well:"Good son, the term 'unconditioned' is also a word provisionally invented by the First Teacher. Now, if the First Teacher provisionally invented this word, then it is a verbal expression apprehended by imagination. And, if it is a verbal expression apprehended by imagination, then, in the final analysis, such an imagined description does not validate a real thing. Therefore, the unconditioned does not exist. Good son, the term 'conditioned' is also invented from language [and it validates nothing real]. "Besides 'the unconditioned' and 'the conditioned,' any other expression that exists in language is the same. But [some may object], is it not true that there are no expressions without some [corresponding] reality? What then is that reality here? I would reply that it is that reality apart from language and realized in the perfect awakening of the saints through their wisdom and insight apart from all names and words. It is because they desire to lead others to realize perfect awakening that they establish [such expressions] as 'the unconditioned' as verbal descriptions."
As we can see Keenan is able to get the two points that Tillemans objects to in Power’s translation correct here. Cleary is a bit closer, but Keenan is still the clearest and most precise here."That does not mean, however, that there is nothing being discussed. What is that thing? Sages, with their knowledge and vision, detach from names and words, and therefore actualize enlightenment. Then, because they wish to make others aware of this nature that is beyond words, they temporarily set up names and characteristics and call something created.”
The next passage Tillemans discusses in his review of Powers is in Chapter 5, page 71 of Powers:
Tillemans writes:"Viśālamati, consciousness is also called the 'appropriating consciousness' because it holds and appropriates the body in that way. It is called the 'basis-consciousness' because there is the same establishment and abiding within those bodies. Thus they are wholly connected and thoroughly connected. It is called 'mind' because it collects and accumulates forms, sounds, smells, tastes, and tangible objects.
Now let’s look at Keenan’s rendering of the passage (Keenan, p. 28):…this passage has been discussed by Lambert Schmithausen in his Alayavijñana: On the Origin and Early Development of a Central Concept of Yogacara Philosophy (Tokyo, 1987), who on his p. 22 translates as follows: "[The mind-containing all-seeds] is also called 'alayavijndna' because it sticks to and dissolves into or hides in the body, in the sense of sharing its destiny (i. e. becoming closely united with it).” Powers regrettably missed all this. If we look at Powers's understanding of the syntax of the passage, it should be clear that breaking the sentence at grub pa dang bde ba gcig pdi don gyis, not translating the don gyis = arthena and then starting a new sentence with 'Thus . . ." is quite unacceptable: making two arguments here, where there is only one etymological explanation, deforms the passage badly. In fact, SNS passage asserts that the consciousness in question can be called alayavijnana because it clings to and hides in the body in the sense of sharing the body's same yogaksema ("fate," "welfare," "destiny"). Schmithausen devotes a considerable part of his monograph to the question of just what was this early or even initial conception of the alayavijnana "sticking to" and " being concealed in" the body.
And Cleary (p. 19-20) for completeness:"Visalamati, this consciousness is also termed the appropriating consciousness, because it is taken up together with the body. It is also termed the receptacle consciousness, because this consciousness joins itself to and lies hidden [in that body] in a common security and risk. It is also termed mind, because this consciousness mines and accumulates material forms, sounds, odors, tastes, and touches.
Clearly, Keenan is once again closer to the meaning as outlined by Tillemans and Schmithausen here. It also makes much more sense on the face as a cold reading than the Powers, for it is not easy to see what “there is the same establishment and abiding within those bodies” could mean without further commentary but “this consciousness joins itself to and lies hidden [in that body]” is much easier to understand what is meant. So Keenan is clearly the better choice here as I hope I have shown. Cleary is not as off as Powers in these key passages, but he is not as correct as Keenan either."This consciousness is also called clinging consciousness, because this consciousness follows and clings in the body. It is also called repository consciousness, because this consciousness receives and stores in the body, indifferent to good or bad.”
Now as Tillemans notes “We should stress that much of the text of the SNS is more or less correctly rendered into readable English by Powers and that the Anglophone reader will thus have access to the SNS (although he should exercise caution and healthy skepticism.)”
So this is not to be taken as an absolute trashing of all of Powers translation, however, it is quite obvious that it is not without its problems, and that a preference for the Keenan seems the best option here, at least until a better translation comes along.