Critical thinking

I think that the most important thing that anyone can learn about is critical thinking skills. From there, you can get everything else you need. Schools don't really attempt this in any systematic way, unfortunately --- in large part, because it's difficult. Stanley Fish claims that you can get to clear writing --- with clear thinking tagging along --- via grammar.

Students can't write clean English sentences because they are not being taught what sentences are.

Most composition courses that American students take today emphasize content rather than form, on the theory that if you chew over big ideas long enough, the ability to write about them will (mysteriously) follow. The theory is wrong. Content is a lure and a delusion, and it should be banished from the classroom. Form is the way.

On the first day of my freshman writing class I give the students this assignment: You will be divided into groups and by the end of the semester each group will be expected to have created its own language, complete with a syntax, a lexicon, a text, rules for translating the text and strategies for teaching your language to fellow students.
...
They think I'm crazy. Yet 14 weeks later --- and this happens every time --- each group has produced a language of incredible sophistication and precision.

Hmmnn. I'm always looking for some excuse to learn Lojban.