DEAR MISS MANNERS: A friend surprised me with a book as a gift. As it happened, I already owned a copy of that book, and had read and enjoyed it.
This book was not a best-seller -- far from it -- and my friend could not have expected that. So I laughed at the coincidence and told him the whole truth.
He looked a little chagrined, so I did my best to soften the blow. I praised the gift lavishly -- it really was an excellent book -- and I praised him for knowing the exact kind of book I would like. But I didn't see any point in owning two copies, so I didn't take it. ("Refused" sounds like such a harsh word!) I left it with him (we were at his house at the time) and recommended he keep it and read it himself, or give it to someone else.
By the way, it was not my birthday or any other special occasion. I wasn't expecting a gift at all. I think he just happened to run across a book that was "right up my alley," so to speak, and decided to buy it for me.
Looking back on it, I wonder if I should have accepted the book. What do you say?
GENTLE READER: That you won't be receiving more gifts from this gentleman any time soon.
Yes, Miss Manners confirms your better instinct, that you should have accepted the book. The "whole truth" in reaction to receiving a gift is rarely necessary. The polite thing to do would have been to thank him profusely for his thoughtfulness, say that you know about how good the book is, and then change the subject.
If he directly asks you if you have read it, then you can confess, but even then, you needn't confess voluntarily to owning a copy. As he did not ask, it is up to your discretion to figure out what to do with the second copy, not his.