> I hadn't heard of cost-push inflation before, and I didn't specialize in macro-economics. Who discredited this theory?

Cost-push is described in Reisman's tome "Capitalism" and is shown why it is a false theory starting on pg. 907.

> perhaps your professor meant that he believed in free enterprise, but wanted to use the taxation system to make post-tax income much more equal? If so, there is no contradiction.

I quoted his exact words, and he did not qualify them. In particular he did not say "more equal", he said "equal". I remember it to this day because I was astonished.