The phrase “never judge a book by its cover” or “don’t judge a book by its cover” means that you should not form an opinion about someone or something based only on their outward appearance or what you perceive without knowing the full situation. It is a metaphorical phrase that comes from the idea that you may see the cover of a book and decide it’s not a good book or it’s not worth reading without knowing anything else about it. The phrase can be used in social and professional settings to describe people or objects, and it tells people to reserve their judgment from their first impression.
The phrase was popularized when it appeared in the 1946 murder mystery, Murder in the Glass Room, by Lester Fuller and Edwin Rolfe: “You can never tell a book by its cover.” However, some sources say that it appeared as early as 1860 in George Eliot’s The Mill on the Floss.
Some examples of using the phrase are:
- You can’t judge a book by its cover. She may look shy, but she’s a great singer.
- Don’t judge a book by its cover. That car may look old, but it runs very well.
- He learned not to judge a book by its cover when he met his new boss. He thought he was going to be strict and boring, but he turned out to be friendly and fun.
