Q From Kristin Hatcher, Michigan: I have searched your site but can’t find any information on the phrase speaking out of school. In my experience it is used to indicate that the speaker may not have the right to give the information they are about to give, or even that they are not certain the information is correct. Where did this odd phrase originate?
A I know of three versions of this saying, the other two being talking out of school and telling tales out of school.
The last is by far the oldest: it’s recorded from The Practice of Prelates, a bitter polemic by William Tyndale that was ostensibly about whether Henry VIII’s divorce from Catherine of Aragon was valid. In it, he says, “So what cometh once in may never out for fear of telling tales out of school.” It was presumably by then already a well-known aphorism, as John Haywood included it in his Dialogue Containing the Number in Effect of all the Proverbs in the English Tongue only 16 years later, in 1546.
The usual meaning is, don’t gossip indiscreetly or reveal private matters, secrets or confidences. Telling tales, revealing the misdeeds of a colleague or fellow pupil, has of course anciently been a heinous crime, since it broke the bonds of fellowship and mutual support.
The other two versions are by comparison mere Johnny-come-lately upstarts on the linguistic scene, no more than restatements of the older form. Talking out of school is by a few decades the older. I have an example from a US newspaper in 1863, but it’s recorded — rather obliquely — a little earlier from a British publication:
School politics in Prussia. — The Prussian State Gazette contains an ordinance prohibiting all talking about politics in schools. We are unable to inform our readers whether riding-schools and schools for scandal be included in this prohibition. It, however, appears to us that it would have been much wiser to have prohibited politicians from talking out of school.
The Athenaeum, 17 Aug. 1833. Schools for scandal is clearly enough a reference to the Sheridan play; riding school was a contemporary term for a brothel.
Your version, speaking out of school seems to be natively from the US, as it very rarely turns up in British sources even today, and then usually in the quoted speech of Americans. Here’s a recent example of it:
So, if Biden wasn’t acting at the behest of the White House, the next question is whether he was simply speaking out of school, which he has turned into something of a cottage industry over his long political career, or whether he was doing a bit of 2016 positioning.
Washington Post, 11 May 2012. Vice President Joe Biden had announced his support for same-sex marriages before President Obama did so.