Here's a brief history, as I (Pat Farenga) understand it, of how John Holt coined this word and concept when he published it in Growing Without Schooling for the first time.
"Unschooled" is an old word. The Oxford English Dictionary cites its first use in 1594 and defines it:
1. Uneducated, untaught. b.) Not educated at school; not made to attend school.
2. Untrained, undisciplined. b.) Not affected or made artificial by education; natural, spontaneous.
3. Not provided with a school.
Holt probably wanted to bring out the second, less popular meaning of the word (if he used a dictionary at all for coming up with it!), to indicate that being unschooled meant you learned in natural, spontaneous ways, as well as the third meaning (no school). However, just as Illich's use of the word "deschooling" has led people who hear the word without reading his book (Deschooling Society) to conclude Illich wanted to abolish all schools, so has Holt's use of the word "unschooling" led people to conclude, without reading Holt's work, that unschooling will create uneducated people. Indeed, as a writer who sought simplicity and clarity in his word choices, Holt moved away from using "unschooling" in his writing and work over the years and used "homeschooling" as the more generally understood term for learning without going to school. In the 1981 first edition of Teach Your Own, Holt approved this index entry: "Unschooling: see Home Schooling."
Unschooling is actually defined by Holt in GWS #2: "GWS will say ''unschooling" when we mean taking children out of school, and "deschooling" when we mean changing the laws to make schools non-compulsory and to take away from them their power to grade , rank , and label people, i.e., to make lasting , official, public judgments about them." However, Holt's precise definition often gets conflated with his general philosophy about how children learn and what adults can do to best help them, causing people to forget that Holt deliberately defined unschooling very inclusively.
I've been asked to define unschooling since 1981. The simple answer I learned from John is unschooling is NOT school. John Holt was tuned into popular cultureand during the 1970s there was a popular television commercial for a soft drink called 7-Up. The marketing hook for 7-Up was that it was "The Uncola"—clear to look at, refreshing to the palate—it was NOT a syrupy cola. When John was casting around for words to describe learning without going to school the Uncola campaign was in full swing and it could have influenced him.
Unschooling never caught on as Holt intended the word to, but throughout the next two decades unschooling increasingly became identified as a rubric for all of Holt's ideas and work. In 2003, when I updated Teach Your Own, I attempted a concise definition based on the increased use of the word in media, parenting, and education circles since Holt died in 1985:
This is also known as interest driven, child-led, natural, organic, eclectic, or self-directed learning. Lately, the term "unschooling" has come to be associated with the type of homeschooling that doesn't use a fixed curriculum. When pressed, I define unschooling as allowing children as much freedom to learn in the world, as their parents can comfortably bear. The advantage of this method is that it doesn't require you, the parent, to become someone else—a professional teacher pouring knowledge into child-vessels on a planned basis. Instead you live and learn together, pursuing questions and interests as they arise and using conventional schooling on an "on demand" basis, if at all. This is the way we learn before going to school and the way we learn when we leave school and enter the world of work. So, for instance, a young child's interest in hot rods can lead him to a study of how the engine works (science), how and when the car was built (history and business), who built and designed the car (biography), etc. Certainly these interests can lead to reading texts, taking courses, or doing projects, but the important difference is that these activities were chosen and engaged in freely by the learner. They were not dictated to the learner through curricular mandate to be done at a specific time and place, though parents with a more hands-on approach to unschooling certainly can influence and guide their children's choices.
Unschooling, for lack of a better term (until people start to accept living as part and parcel of learning), is the natural way to learn. However, this does not mean unschoolers do not take traditional classes or use curricular materials when the student, or parents and children together, decide that this is how they want to do it. Learning to read or do quadratic equations are not "natural" processes, but unschoolers nonetheless learn them when it makes sense to them to do so, not because they have reached a certain age or are compelled to do so by arbitrary authority. Therefore it isn't unusual to find unschoolers who are barely eight-years-old studying astronomy or who are ten-years-old and just learning to read.
—From Teach Your Own: The John Holt Book of Homeschooling by John Holt and Patrick Farenga
Some unschoolers take exception with my definition because they feel it is confusing and will be used against children by parents who "can't bear" children's actual freedom. I think this is a willful misreading of my intent, which is to show that unschooling does not resemble school learning and that parents and children can learn and grow cooperatively. As Aaron Falbel wrote in The Legacy of John Holt, "John trusted parents to learn from their experience with their children. He didn’t say, 'If you’re going to call it unschooling, you’re going to have to do it my way.' He wanted them to figure out what was right for them, for their whole family."
Since Holt first used the word in 1977, unschooling has also been defined by some religious homeschoolers and educators as "child worship," or letting the children run the show, and so on. However, unschooling is not unparenting; freedom to learn is not license to do whatever you want. People find different ways and means to get comfortable with John Holt's ideas about children and learning and no one style of unschooling or parenting defines unschooling, as the following selection of books demonstrates. — PF (updated, 2013)
Homeschooling With Gentleness: A Catholic Discovers Unschooling (2004) by Suzie Andres
Homeschooling Our Children, Unschooling Ourselves (2002) by Alison MacKee
Christian Unschooling (2001) by Terri Brown with Elissa M. Wahl
The Unschooling Handbook by Mary Griffith (1998)
The Teenage Liberation Handbook (1998) by Grace Llewelyn
Real Lives: Eleven Teenagers Who Don't Go To School Tell Their Own Stories (2003) by Grace Llewelyn