In "A School Master for a Great City", Angelo Patri writes:

I realised then that the child must move and not sit still : that he must make mistakes and not merely repeat perfect forms: that he must be himself and not a miniature reproduction of the teacher. The sacredness of the child’s individuality must be the moving passion of the teacher.

Angelo could be writing this material today, in response to the current education reform movement. He’s not, he wrote this in 1917 in response to what was his reform movement in education during his time. Alec Couros recommended that I read this book, making the observation at the time that education never seems to get anywhere because each generation forgets the lessons of the previous generation. We keep going through cycles of reform based on "traditional methods" and reform based on "progressive methods."

Angelo Patri was attempting to reform his own practices, and struggled under one principal, but then worked for another principal who was much more progressive, and gave him this advice:

You must not think too much of arithmetic, and rules and dates and examinations, for these are not teaching; the children don’t grow because of them. They grow because of their contact with you, the best that you know and feel.

Why won’t we heed this advice, given nearly a hundred years ago? What makes us repeat the mistakes of the past over and over again? As Einstein said, "Insanity: doing the same thing over and over again, and expecting different results."