4.5/5. This is the third book in Bataille's "Summa Atheologica" (Inner Experience and Guilty were the first and second. I'm not sure how many books he planned for it, but the rest of the work he did for it, I believe, is collected by Stuart Kendall's compilation "The Unfinished System of Nonknowledge". I think some stuff is also in "The Impossible"). It is split into three parts: Mr. Nietzsche, Summit and Decline, and (what takes up roughly 2/3rds of the book) Diary (February-August 1944). Like "Guilty", this is Bataille at his most human, his most sincere. He often describes how much pain he's suffering, how depressed he is, how anxious he is, how he's often lonely: and who could blame him? This was the "summit and decline" of the Nazi occupation of France and Bataille was battling tuberculosis the entire time of the writings.
The title is slightly misleading, at least it was for me, as I thought it might be Bataille's explications on Nietzsche's thought. This is somewhat true, but as Kendall notes in the introduction it is more of an expansion of his thought, to out-Nietzsche Nietzsche, to be "more Nietzchean than Nietzsche."
The main theme of this book seems to be morality, but it is quickly tied to "going beyond being" which includes communication and the ruptures in communication (laughter, sobbing, death, ecstasy, among other things). Bataille's concept of the moral summit was very intriguing to me, but really the best part of this book is the diary. We read about Bataille's fear of death (which he calls nothingness, particularly an "immanent nothingness", which he describes as going beyond being) and his overall negative state of mind, yet he chooses (or so he says) to laugh at his circumstances; to laugh at chance.
Chance plays a bigger role in this book than in Guilty. His thoughts on chance are extremely good to me, and I like his categorization of chance as a "series of interferences" separating being from nothingness. I think at one point he deems chance a (quasi-)God, perhaps in the spirit of Nietzsche and his previous Acephale project of trying to find a new religion, except there's pretty much no tenets other than a Nietzschean life-affirming laughter at everything that happens to you. I suspect it's not a literal laughter, but more of a joyous acceptance (I think in the notes he pretty much says joy and anguish are the same, following Nietzsche's queue that the supreme good and supreme evil are equivalent).
Overall, I thought this book was very good and the Summa Atheologica trilogy, taken as a whole, is probably the best of Bataille I've read. Definitely requires multiple re-readings: especially Inner Experience.