Books are frozen voices, in the same way that musical scores are frozen music. The score is a way of transmitting the music to someone who can play it, releasing it into the air where it can once more be heard. And the black alphabet marks on the page represent words that were once spoken, if only in the writer’s head. They lie there inert until a reader comes along and transforms the letters into living sounds. The reader is the musician of the book: each reader may read the same text, just as each violinist plays the same piece, but each interpretation is different.

So when you give a well-loved book to someone else, it is above all an act of trust: you are trusting the recipient not to massacre the book in his or her interpretation of it. Tonight , therefore, we will be witnessing not only a million Quixotic acts of giving, but a million Quixotic acts of trust.

“Go, little book,” authors used to tell their creations, in the end-of-the-book convention called the envoi . “Into the hands of strangers I confide you.” And when we give away a book we have loved, this is what we ourselves are thinking: Farewell, we wish the book. May your new owners treat you well; may they not throw you against the wall or use you for kindling. May they pardon your faults and praise your virtues. May you bring wisdom or knowledge. May you bring joy.