Against All Things Ending - 2010
The Last Dark - 2013

http://en.wikipedia.org/wiki/Thomas_Covenant :

From Thomas Covenant's perspective, the Land may be only a delusion of his disturbed mind. Stephen R. Donaldson goes to great lengths to make this just as plausible as any other theory (e.g., Thomas Covenant is indeed mentally unbalanced, events in the Land seem to parallel his subconscious struggles, his physical condition upon exiting the Land is always precisely identical to his condition upon entering the Land, etc.) This raises the 'Fundamental Question of Ethics' that appears at the very start of the Chronicles, which can be rephrased as "do actions performed in dreams have any significance?" A deplorable act performed by Covenant in the first book (which will have consequences throughout the story) can be seen as an attempt to test this theory. One interpretation of the First Chronicles sees the reality of the Land eventually 'proven' to Covenant; another interprets Covenant's eventual decision to act for the Land as understanding that, be the Land real or not, it is of significance to him. Covenant tried to test the reality of the land several times during the first and second chronicles by growing a beard (after choosing not to discard his pen knife, the only object he has with him apart from his clothes) however this fails when he inevitably shaves his beard. Another test of the reality of The Land is the fact that Covenant enters the land after sustaining damage (e.g. being hit by a car in the first book, bashing his head on a coffee table corner in the second and a series of incidents at the start of the third including cutting his gums on razor blades hidden in bread buns, falling down a stoney hill, and sucking snake poison from the wound of a young girl) but he is always returned to the same state that he entered shortly before leaving, such as the wound on his forehead that he sustains bashing it on a coffee table before entering the Land is healed, only to be wounded again after being attacked with a staff by Hile Troy (Another 'real person' who has entered the Land.)[original research?]
Another major theme, closely related to the one just mentioned, is the psychological symbolism of the Land. It very clearly parallels Covenant's own psyche: he is filled with self-hatred, manifested in the Land as the Despiser; he is ravaged by a corrupting disease that eats away at him, similarly to the Illearth Stone, and so forth. Covenant is forced to decide whether the fundamental health and beauty of the Land is worth struggling to preserve, whether it's "real" or not, mirroring the choice he must make in his own life. In this way the fantasy genre allows the author to explore Covenant's inner workings in a very effective way.
After his return to our world, Covenant resumes his writing, publishing seven novels in ten years. Although he will never be able to return to the life he had before contracting leprosy, he seems to have come to terms with his condition and the events that transpired in The Land.

Where the First Chronicles were involved with Covenant himself, his psychology, and his relationship with the world of the Land, the Second Chronicles add a second character, Linden Avery. The interaction of the two characters becomes a major topic, with relations warming up and cooling off at different times, but in the end settling on mutual respect and warmth. Covenant is forced to re-evaluate his experiences and the conclusions he's come to in another context, namely when other "real" peoples' "real lives" are affected.
The resolution of the crisis and the defeat of the Despiser reveal another theme. Covenant discovers despite in himself, and thus that the Despiser is part of him, in a sense (figuratively, or, perhaps, even literally). Thus he does not need to combat him directly - indeed, direct conflict failed to defeat the Despiser more than once. Hence he surrenders his ring to the Despiser, and allows him to fail in his attempt to destroy the Arch of Time.

In the Thomas Covenant stories, Donaldson takes several terms from Sanskrit that are significant in Hinduism and Buddhism and reassigns them meanings in the Land. For example, the term moksha, which in Sanskrit refers to liberation from the cycle of sorrow, is given as the original name for a creature of depravity and evil called a Raver. Another Raver, Satansfist, is called samadhi, which in Sanskrit refers to a state of mind in which one achieves oneness with the object of one's concentration. The third Raver, Kinslaughterer, is called turiya, Sanskrit for a state of pure consciousness. Donaldson has commented on his website that moksha, samadhi, and turiya are ways the ravers describe themselves, while their other names are given by others.[1] Note that Donaldson's use of the term "raver" preceded the modern rave culture, so their overlap is likely coincidental.
Donaldson repeats this application of Sanskrit terms to seemingly unrelated aspects of the Land to other terms, including: dukkha, dharmakshetra, ahamkara, and yajna.
The Chronicles also contain names of Semitic origin. For instance, samadhi/Satansfist is also called "Sheol", (Hebrew for the grave, the abode of the dead), moksha/Fleshharrower is also known as "Jehannum" (similar to the Hebrew "Gehinnom" and the Arabic "Jahannum", for Hell or Purgatory), and turiya/Kinslayer is also "Herem" (Hebrew for banned, excluded, excommunicated). The name of the fairy race of Elohim is the Hebrew for God or gods.
The name Bhrathair (for one of the peoples encountered by Covenant in his sea voyage) is Irish for "brothers".