The Simple Art of Murder comprises the essay of the same name and four early non–Philip Marlowe stories (in some editions, there are eight stories). The essay is justifiably famous and worth reading; the stories are of middling quality.
All are available online: The Simple Art of Murder Essay, Spanish Blood, I’ll be Waiting, The King in Yellow, and Pearls are a Nuisance.
In the essay, Chandler takes aim at the sterile confections of deduction that comprised most detective fiction written in the 1920s and 1930s, which “do not really come off intellectually as problems, and they do not come off artistically as fiction.” He contrasts that with the realistic style of Dashiell Hammett, who “gave murder back to the kind of people that commit it for reasons, not just to provide a corpse; and with the means at hand, not with hand-wrought duelling pistols, curare, and tropical fish.” He concludes: “In everything that can be called art there is a quality of redemption. It may be pure tragedy, if it is high tragedy, and it may be pity and irony, and it may be the raucous laughter of the strong man. But down these mean streets a man must go who is not himself mean, who is neither tarnished nor afraid. The detective in this kind of story must be such a man …”
Pearls are a Nuisance is a story of the kind that Chandler complained about. More precisely, it’s a parody of such stories, with a well-spoken gentleman teaming up with a hard-drinking ruffian to retrieve the purloined pearls of Mrs Penruddock. It’s the weakest story in the book.
The other three stories are classic Chandler, tales of moral ambiguity that are whydunnits, not whodunnits. In Spanish Blood, a hardboiled cop investigates the political murder of an old friend. I’ll be Waiting‘s sad house detective tries and fails to save a man. The King in Yellow‘s private eye discovers a mess of frameups and revenge.