"We believe that we invent symbols. The truth is that they invent us; we are their creatures, shaped by their hard, defining edges. When soldiers take their oath they are given a coin, an asimi stamped with the profile of the Autarch. Their acceptance of that coin is their acceptance of the special duties and burdens of military life--they are soldiers from that moment, though they may know nothing of the management of arms. I did not know that then, but it is a profound mistake to believe that we must know of such things to be influenced by them, and in fact to believe so is to believe in the most debased and superstitious kind of magic. The would-be sorcerer alone has faith in the efficacy of pure knowledge; rational people know that things act of themselves or not at all."
-- The Shadow of the Torturer, from http://world.std.com/~pduggan/wolfe.html
A set of four books by Gene Wolfe, comprised of:
1. The Shadow of the Torturer
2. The Claw of The Conciliator
3. The Sword of the Lictor
4. The Citadel of the Autarch
There is also a "sequel" to the four books: The Urth of the New Sun, which is not strictly necessary to the plot, but explains some things in more detail.
The book of the new sun is the autobiography of Severian, who is also Thecla, a young woman who Sevarian murdered and then absorbed into himself by eating her brains.
It's interesting to note that there are several parts of the story which Sevarian never reveals. What is the name of the Autarch? Who is Sevarian's mother?