HERE is a terrific piece by Daniel Quinn on the history of "public education" and the motives behind it, as well as an affirmation of the natural curiosity of children -- who do NOT need motivation to learn. It is a testament to unschooling.
Here's a quote from the speech:
"What sells most people on the idea of school is the fact that the unschooled child learns what it wants to learn when it wants to learn it. This is intolerable to them, because they're convinced that children don't want to learn anything at all - and they point to school children to prove it. What they fail to recognize is that the learning curve of preschool children swoops upward like a mountain - but quickly levels off when they enter school.
"By the third or fourth grade it's completely flat for most kids. Learning, such as it is, has become a boring, painful experience they'd love to be able to avoid if they could. But there's another reason why people abhor the idea of children learning what they want to learn when they want to learn it. They won't all learn the same things! Some of them will never learn to analyze a poem! Some of them will never learn to parse a sentence or write a theme! Some of them will never read Julius Caesar! Some will never learn geometry! Some will never dissect a frog! Some will never learn how a bill passes Congress!
"Well, of course, this is too horrible to imagine. It doesn't matter that 90% of these students will never read another poem or another play by Shakespeare in their lives. It doesn't matter that 90% of them will never have occasion to parse another sentence or write another theme in their lives. It doesn't matter that 90% retain no functional knowledge of the geometry or algebra they studied. It doesn't matter that 90% never have any use for whatever knowledge they were supposed to gain from dissecting a frog. It doesn't matter that 90% graduate without having the vaguest idea how a bill passes Congress. All that matters is that they've gone through it!"