These two books, considered as a unit, in turn make up the second volume of a trilogy under the overall title of After Such Knowledge. The first volume is a historical novel called Doctor Mirabilis; the last, a science-fiction novel called A Case of Conscience. These two volumes are independent of each other and of Black Easter and The Day After Judgment, except for subject matter; that is, they are intended to dramatize different aspects of an ancient philosophical question which is voiced by Baines in Chapter VIII of the present work. As before, the books of magic cited in the text all actually exist (although mostly in manuscript), and the magical rituals and diagrams are all taken from them (although in no case are they complete). The characters and events, on the other hand, are entirely my own invention, as are all the details about the Strategic Air Command. —James Blish, Harpsden (Henley), Oxon., England, 1970 If you've enjoyed this book and would like to read more great SF, you'll find literally thousands of classic Science Fiction & Fantasy titles through the SF Gateway.
