The Island of the Day Before

I read The Island of the Day Before, the 1994 novel by Umberto Eco, thinking it was a fantasy of sorts or at least had fantasy elements. It's not a fantasy in the usual sense of the word, though much of the action takes place in the protagonist's mind and is treated in a way as if it really happened. It's an odd book. It's more enjoyable as an intellectual exercise than as a novel. I didn't enjoy the sections that dwelt on philosophical Astronomy and the concept of longitude, and that was much of the book. I found those sections tedious and caught myself skimming them. I liked the last part of the book more.

my favorite quotes from late in the book:

So here I am illuding myself with the illusion of an illusion -I, an illusion myself? I who was to lose everything, happened on this vessel lost in the Antipodes only to realize there was nothing to lose? But, understanding this, do I not perhaps gain everything, because I become the one thinking point at which the Universe recognizes its own illusion?

and

But in the final analysis, what is this I that I believe thinks me? Have I not said that it is only the awareness of the Void, identical to extension, has of itself in this particular composite? Therefore I am not I who thinks, but I am the Void, or extension, that thinks me. And so this composite is an accident, in which Void and extension linger for the blink of an eye, to be able afterwards to return to thinking otherwise. In this great Void of the Void, the one thing that truly is, is the history of this evolution in numberless transitory compositions. . . . Compositions of what? Of the one great Nothingness, which is the Substance of the whole.

Substance governed by a majestic necessity, which leads it to create and destroy worlds, to weace our pale lives. I must accept this, succeed in loving this Necessity, return to it, and bow to its future will, for this is the condition of Happiness. Only by accepting its law will I find my freedom. To flow back into It will be Salvation, fleeing from passions into the sole passion, the Intellectual Love of God.

If I truly succeeded in understanding this, I would be the one man who has found the True Philosophy, and I would know everything about God that is hidden. But who would have the heart to go about the world and proclaim such a philosophy?

from the back of the book:

I am, I believe, alone of all our race, the only man in human memory to have been shipwrecked and cast up upon a deserted ship.

So begin the journals of Roberto della Griva, a seventeenth-century nobleman who finds himself on board a mysterious ship anchored in the bay of a beautiful island he cannot reach. The story of how he got there, and what he finds on board, are just a part of this exquisitely crafted novel that celebrates the romance, war, politics, philosophy, and science of the Baroque period in all its lush and colorful detail

There is a reading group guide with discussion questions here. The review at The Guardian says it put him to sleep and closes with this:

On the marooned ship Daphne, Father Caspar and Roberto debate ad nauseam the implications of parallel worlds. There appears to be a world in which Eco is regarded as a significant and influential writer. If it is this one, I'd like to relocate.

Kirkus Reviews ends by saying, "Though weighted here and there by the longueurs of whimsy, this is on balance an intriguing and entertaining theoretical rompa kind of Borgesian Robinson Crusoe."

PhiloBiblios calls it "difficult to review" and says,

I read through the entire book thinking that surely something would happen soon, that there was some missing element that would make itself known and make the book pop like some of Eco's others have for me. And that never happened

but says Eco's books are all worth reading for their interesting explorations of philosophical and historical issues.