They may teach very well, and more than earn their salaries, but most of them make little or no independent reflections on human problems which involve moral judgment.
It wasn't until 1906 that a scholar came across the prayer book in a library and realized it was a palimpsest, and that the underlying layer of texts could only have come from Archimedes.
The mill owners were looking for a way to replace the workers with unskilled labor, and needed an automatic mule, which did not need to be controlled by the spinner.
There's a subtle decency to most of Cotten's work, though it can curdle into cynicism pretty fast, and his characters often get crushed by the looming failure of their dreams.