[genofon]

>Looking back over the past couple of hundred years of us overcoming challenge after challenge, and drawing the conclusion that it is absolutely certain that can't happen more, is simply an absurd position to take on a rational basis.

Looking a bit further there were society completely destroyed by themself (for example Easter Island http://www.sciencelearn.org.nz/News-Events/Latest-News/News-...)

It's good to have both forces, a conservative and a progressive, to maintain equilibrium, it's never a good idea to put all the eggs in one basket

Edit: update link about Easter Island