I understand what you're saying here and when I teach calculus I ask my students to show their work. A couple of comments:
No, the purpose of "showing your work" is not for The Man to keep you down. It's to demonstrate that you didn't just copy your answers from someone else (or from a calculating device). It can be tedious, yes, but so long as students do copy answers I don't grudge the teachers this method of making that more difficult.
I agree that this is reasonable given how educational institutions are structured (in particular, given how much emphasis is currently placed on evaluation) but think that there's a general problem of focus on evaluation being detrimental to quality of education. My experience teaching calculus discussion sections has been that my students' focus on getting good grades takes up so much of their attention that they have little attention to bring to the task of actually learning the material. On the flip side circumstances force instructors to devote so much of their time to ensuring that grading is fair that their ability to focus on actually teaching is markedly impaired. I see the common focus on deterring cheating as part of this dynamic. This is not to say that I have a solution, I'm just saying that's Something's Wrong :-).
So this justification only applies if you're always correct or the teacher is entirely unable or unwilling to teach (granted, sometimes true, but not always). Also that you're not proving anything--because if you can't write down your reasoning, why on earth do you expect anyone to believe your conclusion? That it's difficult is not sufficient reason not to do it.
It seems likely to me that Thurston is Generalizing From One Example here. He's legendary for having consistently made obscure and apparently ungrounded statements which have turned out to be fully justified. One could imagine such a background making it easy to forget that not everybody is the same way.
In Jaffe and Quinn's "Theoretical mathematics'': Toward a cultural synthesis of mathematics and theoretical physics the authors say
William Thurston’s “geometrization theorem” concerning structures on Haken three-manifolds is another often-cited example. A grand insight delivered with beautiful but insufficient hints, the proof was never fully published. For many investigators this unredeemed claim became a roadblock rather than an inspiration.
The full proof of the geometrization theorem for Haken manifolds was later published along the lines that Thurston had originally suggested. Thurston responded to Jaffe and Quinn in his essay titled On proofs and progress in mathematics.
I agree about the overall structure of educational systems vis a vis grades, although there is apparently some evidence that being tested periodically helps one retain information.
It seems likely to me that Thurston is Generalizing From One Example here.
Actually, in fairness, I don't think he's generalizing; I think he's observing one example. My interpretation of the statement as prescriptive may not have been intended. Of course, if it's to be included on this list, it should be expected to be interpreted as prescriptive.
...He's legendary for having c
Most people form their impressions of math from their school mathematics courses. The vast majority of school mathematics courses distort the nature of mathematical practice and so have led to widespread misconceptions about the nature of mathematical practice. There's a long history of high caliber mathematicians finding their experiences with school mathematics alienating or irrelevant. I think this should be better known. Here I've collected some relevant quotes.
I'd like to write some Less Wrong articles diffusing common misconceptions about mathematical practice but am not sure how to frame these hypothetical articles. I'd welcome any suggestions.
Acknowledgment - I obtained some of these quotations from a collection of mathematician quotations compiled by my colleague Laurens Gunnarsen.
In Reflections Around the Ramanujan Centenary Fields Medalist Atle Selberg said:
In his autobiography Ferdinand Eisenstein wrote about how he found his primary school mathematical education tortuous:
There is some overlap between Eisenstein's early school experience and the experience that Fields Medalist William Thurston describes in his essay in Mariana Cook's book Mathematicians: An Outer View of the Inner World:
Thurston's quote points to the personal nature of mathematical practice. This is echoed by Fields Medalist Alain Connes in The Unravelers: Mathematical Snapshots
In Récoltes et Semailles Fields Medalist Alexander Grothendieck describes an experience of the type that Alain Connes mentions: