The Sickness Unto Death
The fifth book to the left is "Fear and Trembling/The Sickness Unto Death."
The Sickness Unto Death was a philosophical work by Kierkegaard that was sometimes paired with Fear and Trembling in a book.
In 2399, this was one of the books in Cristóbal Rios' library in his quarters aboard La Sirena. (PIC: "Broken Pieces")
The Sickness Unto Death (Sygdommen til Døden) was published in 1849.