Vygotsky’s erroneous ideas about the nature of knowledge,
I haven't read the whole thread yet - have to go out the door but will be back and read - but the problem with teachers having degrees in the subject they teach is that not just colleges of education are stuffed with the most radical of leftist teachers, but practically every institution of higher learning is so stuffed. There are very few universities other than a few private colleges that are not flaming cesspools of ultra leftism.
Vygotsky was a Soviet social scientist whose ideas about the “social construction of knowledge” have become fashionable in education circles in the U.S. His ideas are not complete rubbish, but they can’t actually be applied to education without coming perilously close to the denial of objective knowledge, which they turns into if they become a description of what knowledge is, rather than how it is arrived at.