Des Essientes, a debauched noble at the end of his line, in rebellion against the modern world, humanity, and nature itself (the title is variably translated as "Aganist the Grain" or "Against Nature"), sells the family manor and retreats to a country house in order to languish in exquisite hypochondria and nervous affectation. What strength is left to him he expends obsessing over art, literature, design, and even gardening, in dissertations on artificiality and garish morbid splendor that compose most of the book. It is clear that, much as Huysmans seems to mock Des Essientes' finicky, maladapted nature at times, protagonist and author share the book's aesthetic inclinations* and these are what makes this 1884 "novel" a defining work of Decadence, of the entire fin-de-siecle era.
As such, it's a terribly useful record of cultural context, but fortunately the book's pleasures extend beyond the academic and into sheer voluptuous descriptive prose. Unsurprisingly, Des Essientes expends much enthusiasm on a few writers whose incidental prose exceeds their overall literary vision, and this may be the case here. The narrative seems to exists mainly (and is indeed sufficient to) entirely submerge the reader in Des Essientes' overwrought decorating daliances, symphonies of liquour and perfume, orchid gardens, and faux ship-cabin dining chambers. And these sections are as absolutely splendid as they should be. Admittedly, the literary discussions, more removed from immediate detail, leave me a little colder. Especially when he veers into Latin Catholic theological manuscripts, a subject of which I have next to no knowledge or interest in. Yet they exert a strange magnetism for both protagonist and author. Of course, as they observe, blasphemy (reading "against nature" as "against god") only has real meaning from one who is at root a believer.
*Aesthetic inclinations which, all too often, I also share to some extent. My own interest in Decadence begins with the fantastic proto-surrealist work of Symbolist painters like Odilon Redon and Gustave Moreau, both of whose paintings are of special importance to Des Essientes. Specifically, he hangs two Moreau renderings of Salome (who danced before Herod to procure the head of John the Baptist for her mother) in his sanctuary. Moreau painted many versions of this scene and story, but I believe this is one of the (amazing) paintings specifically referred to in the text:
I've collected all of the art referenced in this novel that I could find here