There is no stopping a mistake after it has started. In the preface to my Ancient Ships I gave the history of a blunder that was made by Scheffer in 1654, and is now in four authoritative books of reference. In fact, when I am told that all authorities agree, I feel certain that one of them has blundered, and the rest have followed him without inquiry.
Would anyone know when the phrase "all authorities agree" was first used? I Googled "when all authorities agree" and there were only 4 mentions of it. Does this phrase have a Greek/Latin or earlier original and was adopted in English?