Lanark: A Life in Four Books by Scottish writer and illustrator Alasdair Gray is difficult to categorize within traditional literary genres. However, the book has a few recurring themes that, collectively, could be considered a thesis to the book's diverse stories. Similar to Dante's Inferno, Lanark explores the concept of hell.

The theme of the human soul's struggle to find a higher plane of existence, possibly enlightenment, is evident in many of the stories in the collection. The human spirit, Gray suggests, craves love but always fails to attain it. However, Gray also opines that people try to attain their own concept of love despite failures to reach it.

The setting of hell and the failure to grasp love is reminiscent of the Greek story of Orpheus. Another theme is the subtle political commentary on the idea of utopia. There's the idea that modern society cannot reach utopia due to our civilization's inherent corruption, politically and morally-speaking.

Another interesting theme in the book is the idea of plagiarism. In fact, there is an index in the book citing all of the plagiarized text. Gray believes that art—whether literary or visual art—cannot be bound by legal and social rules. This disregard for the rules is even illustrated in the narrative itself. The titular character breaks the rules of the Institute where he is being held and defies the nefarious Professor Ozenfant. In essence, Lanark embodies the rebellious human spirit who must liberate himself from the authoritarianism of omniscient beings. This could be a criticism of institutions (e.g. government, organized religion, etc.) or authority figures (e.g. dictators, God, etc.).