The first article in Jill Jusko’s twice yearly “Top 10” Industry Week articles about Lean is her own Lessons in Lean Training, in which she quotes consultant Jon Armstrong as saying “individuals first need to know why before they know how. It’s important to start with the principles.” It sounds rational but it isn’t quite as obvious as it sounds. It’s an effective way to teach geometry but not English spelling. In geometry, you arrive at conclusions through logic; in spelling, you memorize arbitrary rules. You don’t learn to spell because of principles but because you won’t get the job you want with a misspelled resume.