This is the first time I've written a book review on my own accord, rather than by assignment from a professor. I'm not an English major, nor do I have a really vast knowledge of literary information. I can't comment much on genres or styles, so everything following this introduction is just my take on the book -- without anything particular to compare it to. I'll try to make it worth reading, and not spoil anything, too.
I should also point out that I'm picky when it comes to books. I usually stick with non-fiction. It's not that I don't have a good imagination (I'm an art student, remember?) -- I just can't take it seriously. Several friends have tried getting me into the Harry Potter series, and I couldn't do it. Same goes for Twilight and all those omigosh-Vampires-in-high-school books. Anyway, moving on to my thoughts.
If you're like me and have a hard time taking fantastic situations in novels seriously, you'll do OK with this book. Alasdair Gray did an excellent job with incorporating rather absurd scenarios with symbolism and realism, so the fantasy didn't make or break the story.
I'm getting ahead of myself. I should start by saying the book is divided into four, out of sequence books. Gray introduces the main character, Lanark, as he's thrust into the dismal city of Unthank. He arrives by train, with no knowledge of his past other than some sand and seashells in his pockets. He becomes acquainted with the elite clique in Unthank, but consistently feels out of place. Void of sunlight and companionship, Lanark is engulfed into the earth.
Next, Lanark struggles with life in "The Institute", where he overcomes a skin disease and eventually turns from patient to doctor. While in the institute, Lanark is told the story of his past life by an oracle. This takes up half of the novel (books one and two). Gray introduces Duncan Thaw, and gives his Bildungsroman (coming-of-age story). Just as Lanark in Unthank, Thaw struggles through life without every finding true companionship or love. You don't exactly feel sorry for Thaw, but you can relate with him. He suffers through various women, does poorly in school, and loses work due to his unwillingness to compromise.
The final book picks up after Lanark learns about his previous life as Thaw, and leaves the institute. He is continually forced into awkward positions after returning to Unthank. At this point, Gray plays with time, and we see the remaining years of Lanark's life unravel and fall apart.
Based on other reviews I've read, and from how I interpreted the novel, books one and two seem to be Lanark (Thaw)'s life. Books three and four represent hell, or another plane of existence that's clearly undesirable. The theme throughout is man's lack of love leading to destruction. One and two show Thaw's personal demise as a result of being unable to love/be loved. Three and four show mankind's failure due to lack of compassion.
“Man is the pie that bakes and eats itself, and the recipe is separation,” is repeated several times in the novel. You'll get it once you read it -- so go do that. I don't want to give away too much. It's not a difficult read. It is rather long, but I finished it in two weeks, so I'm sure you'll manage. My only real complaint is that Gray seems to add a little 'fluff' here and there by describing the settings in scrutinizing detail. At times it was intriguing and necessary, but often it seemed a bit redundant. Still, it's definitely worth a read!