I'm not sure how this book ended up on a list of titles I wanted to read. I must have read somewhere that Casares was a friend and collaborator with Jorge Luis Borges. That alone probably would have been enough to ellicit some interest. As such, Casares is in the same Argentinean fantastic realist tradition. He's a writer like Borges--the same pseudointellectualism behind many of the stories, the same tricks of storytelling--but more long winded. Whereas Borges's stories rarely clock in longer than about ten pages, Casares's pieces clock in around thirty, and The Invention of Morel itself is a novella.
If I were writing a paper on this book, I would focus on the use of time in the collection, particularly in reference to space, eternity, and reality. Many of the stories, indeed, seem to focus on the manner in which time is an illusion. We can collapse time through memory and various tricks of the mind. These tricks can thus establish a kind of eternity, an alternate reality. They can bring the "past" into the present or make the present disappear into some other universe.
The novella The Invention of Morel certainly focuses on this. The invention that Morel is responsible for is some kind of machine that allows people to continue living. It "steals" life and replays it on a continuous loop. But these people are not really people once their souls are stolen. They are shadows of another world that we can see and walk among but that we cannot really interact with. The story itself is not focused as much on the invention, however, as on the narrator's discovery of it. The narrator, for adventure and exploration, goes to an island from which no one has escaped alive. Conceivably he too gets pulled in by Morel's invention, although somehow he manages to pass a missive off to others that becomes the scholarly description of the place. Much of the story focuses on his fascination with one particular woman--one of the illusions--with whom he wishes to forge a relationship.
The novella was not particularly to my taste. I actually much preferred Casares's shorter pieces. My favorite of those pieces was the story "In Memory of Pauline," which details a man's lifelong friendship with a gal and his disappointment as a jilted lover (spoilers follow). It is his expectation that they will marry, but instead, one night, he introduces her to a friend, and this friend and she fall for each other, and that's that. In despair, the narrator goes overseas for a couple of years. When he returns, Pauline is waiting for him. She apologizes for running off with the other man and slips into the narrator's bed. The next day, the narrator goes in search of Pauline and of the story of what's happened during the two years that he's been gone. He finds out that Pauline is in fact dead, that her lover killed her. So this becomes a ghost story. Not so fast. As the narrator puts the facts together, he discovers certain details that cannot have been true. There's a gift that he gave Pauline that shows up in the apartment in a place where it should not be; they make love to the sound of rain but there is no rain on the ground when he goes outside afterward; his image in the mirror is shady; she speaks more like the narrator's friend than the way the narrator remembered her speaking. What he discovers is that Pauline didn't just die but that her lover, now in prison, killed her, jealous of the narrator. It is the narrator's projected jealousy that has visited him. Pauline never loved the narrator, he realizes, and their consummation upon his return was merely an illusion of the jealous man's mind. This is where, of course the mind takes over, changing our conception of time and reality.
I liked the rest of the stories to different degrees, though not nearly as much. "The Future Kings" is about a spy novelist who becomes a spy when he goes to visit some old friends who are believed to be involved in some kind of plot; they turn out to be people who can speak telepathically to seals. "The Idol" involves an antique dealer who gets hold of a wood sculpture with a dog's head that seems to have supernatural powers (to make one fall in love with the owner's daughter, to kill one in one's sleep, etc.). "The Celestial Plot" involves the crossing of parallel worlds, where a pilot lands in a universe where none of his friends know him, while another pilot lands in a universe where he is flying a different plane than the one he took off in, and so on. The paragraph ending of this story summarizes many of the book's themes quite well. It talks of "old notions" of planetary and spherical worlds versus "bundles of parallel spaces and times." "The Other Labryinth" is a story that unfolds slowly and that I found difficult to get through, but the last ten pages upend the entire piece, and what one thought one was reading turns out to be something entirely other. In the story, a man is obsessed with a manuscript that may or may not be a fraud. We think we know that the fraud was put upon the man by his rival, but the true author of the fraud turns out to be someone quite different. And in "The Perjury of Snow," a poetry critic recounts the murder of a famous poet; as with the previous story and several others in the collection, our perception of the tale is changed significantly at the end, when the interpretation offered of the story of the murder is upended so that another murderer is revealed. And as in those others stories, time plays a key role here, as one man cuts his family off from the rest of the world in order to impose an eternity on his loved ones so that his daughter won't die. It is when that outside world impinges on that man's house, that time reestablishes its power over the family's life.