That's a great quote. I also like this following paragraph about symbols from one of my favorite fantasy authors, Gene Wolfe:
"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."
SPOILER on relevancy:
The narrator just saved a rebel's life in the first chapter, and the rebel repaid him with a coin. Throughout the book the narrator (a torturer) thinks about the coin in his pocket, and he sees it as a bond between the rebel leader and himself. At the end of the first novel he is captured by the rebel's men and works beneath him to destroy the Autarch (King) and restore a fairer system that will rebuild the world (all of this happens on Earth thousands of years from now, while the Sun is about to die, and technology is seen as magic). It eventually turns out that the coin is a fake, and he comes to believe he shouldn't have saved that rebel's life. It's all beautifully told: the coin theoretically was a symbol he invented, yes, but since it had no connections with reality, he remained blind to its influence.