Bret Victor questions the effectiveness of educators that do not actively participate in the subjects they teach in his essay Some Thoughts on Teaching.
Can you trust a teacher who doesn’t use what he teaches? Who has never used what he teaches?
Can you trust a teacher whose only connection to a subject is teaching it?
How can such a teacher know if what he’s teaching is valuable, or how well he’s teaching it? (“Curricula” and “exams”, respectively, are horrendous answers to those questions.)
Real teaching is not about transferring “the material”, as if knowledge were some sort of mass-produced commodity that ships from Amazon. Real teaching is about conveying a way of thinking. How can a teacher convey a way of thinking when he doesn’t genuinely think that way?
I’m sure many teachers spend their evenings thinking about teaching the subject. I have no doubt that these teachers love teaching, and love their students. But to me, that seems like a chef who loves cooking, but doesn’t love food. Who has never tasted his own food. This chef might have the best of intentions, but someone in need of a satisfying meal is probably better off elsewhere.
This idea is great for specialized subjects and higher education in general, but how can it apply to the teaching of children? There are not many practicing mathematicians who would be satisfied teaching basic arithmetic or artists teaching finger painting.