If a teacher knows all about the stars, and knows how to get his message across, he should be qualified to teach astronomy. Well, maybe toss in there that he will, as well, need to know how to control a class.
But, isn't that what a good teacher boils down to -- someone who knows his topic and knows how to teach it? So, why should we shy against hiring someone if we can see they know the topic and they know how to teach it?
Are we going to send them back out the door, telling them, "Sorry, I need someone who carries a piece of paper you just don't have"?
Yep, we are, and something seems wrong with that, to me.
I do not know but what our current system of selecting teachers fails us, at times. Yes, having them go through four years of college and get teaching credentials is a way of vetting them. But, is it the best way? When it comes time to select teachers, we are not looking for those who know the most about biology or math or history, if they are going to teach biology or math or history. Instead, our focus is more on whether they went to college and are credentialed. If they did and they are, and their demeanor is found to be acceptable, they are hired. That becomes our criteria. I would guess sometimes we don't even grill them on what they know about biology or math or history. We miss the focus it takes to find the very best teachers.
If being a good teacher is no more than knowing the topic and knowing how to teach it, why not simply make that the criteria? Why not seek out candidates on that basis, alone? Why be afraid of hiring on that basis, alone? It's all you want in a good teacher; It's all you need in a good teacher. Why shift from making that your goal when you hire your teacher?