It's the idea that people living close to nature tend to be noble. It's seeing all those sunsets that does it. You can't watch a sunset and then go off and set fire to your neighbor's tepee. Living close to nature is wonderful for your mental health.
I have no faith in human perfectibility. I think that human exertion will have no appreciable effect upon humanity. Man is now only more active - not more happy - nor more wise, than he was 6000 years ago.
In school we learn that mistakes are bad, and we are punished for making them. Yet, if you look at the way humans are designed to learn, we learn by making mistakes. We learn to walk by falling down. If we never fell down, we would never walk.