Blish uses the standard techniques of the science fiction of his day but to those techniques he adds an erudition which cannot be found elsewhere in the genre. Off and on throughout the novel, for example, Father Ruiz-Sanchez reads from and meditates upon an extremely convoluted and difficult novel which readers are told has been put on the Index because of the moral ambiguity which is at its heart. The book, which readers only later learn is James Joyce's Finnegans Wake, involves a series of incredibly confusing moral issues, or cases of conscience. An enormous number of characters are implicated in a series of crimes and errors (all of which interrelate with each other) and Ruiz-Sanchez's purpose in reading the book seems to be to analyze the situation and demonstrate logically the exact state of each character's moral involvement. The complexities of Finnegans Wake (1939), of course, mirror the...