I remember taking History of Economic Thought in college over 30 year ago and thinking it was the most boring course I had ever taken. From Aristotle to Arrow, it was full of every discredited economic theory man had ever thought of. The type of boring facts you memorize for the test and forget. I forgot most all of it, except for one.
It was the most iconic of all the faulty theories, that of Thomas Malthus, that man would always doom himself to famine, disease, and war, because man reproduced too quickly for his environment.