Throughout human history, societies, civilizations have prospered and collapsed over time. The reasons, obviously, have lessons for the whole of our intricately interlinked planet today. Eminent professor Jared Diamond, Professor of Physiology at UCLA, gave a speech at Princeton University about the collapse of ancient societies. "Why did these ancient civilizations abandon their cities after building them with such great effort? Why these ancient collapses? Why is it that some societies collapsed while others did not collapse?" | 
