seeing is believing

Actually seeing or witnessing something, as opposed to simply being told about it, allows or will allow one to believe that it is true or has occurred. A: "We've overhauled the design into something that everyone will love." B: "That sounds great, but seeing is believing." A: "The kids say they've kept the house immaculate since we've been gone." B: "Hmm, seeing is believing."

Prov. It is hard to believe something you have not seen. (Implies that you will not believe the thing under discussion until you have actually seen it.) Jill: They say Melissa has become a wonderful housekeeper now that she has her own apartment. Jane: Seeing is believing. I really didn't think that Jerry's girlfriend could be as pretty as he said she was, but seeing is believing.

Only physical or concrete evidence is convincing, as in She wrote us that she's lost twenty pounds, but seeing is believing. This idiom was first recorded in this form in 1639.

Only concrete proof is convincing. The idea dates from ancient Greek times, and the expression appears in numerous proverb collections from 1639 on, in English and many other languages. Some writers disagree. Jesus told his doubting disciple, Thomas, that it was more blessed to believe without seeing (John 20:29). Also, “Seeing is believing, says the proverb . . . though, of all our senses, the eyes are the most easily deceived” (Hare, Guesses at Truth, ca. 1848), and, “Seeing is deceiving. It’s eating that’s believing” (James Thurber, Further Fables for Our Time, 1956).