"Mearsheimer writes ANARCHY on the board, explaining that the word does not refer to chaos or disorder. “It simply means that there is no centralized authority, no night watchman or ultimate arbiter, that stands above states and protects them.” (The opposite of anarchy, he notes, borrowing from Columbia University’s Kenneth Waltz, is hierarchy, which is the ordering principle of domestic politics.) Then he writes the uncertainty of intentions and explains: the leaders of one great power in this anarchic jungle of a world can never know what the leaders of a rival great power are thinking. Fear is dominant. “This is the tragic essence of international politics,” he thunders. “It provides the basis for realism, and people hate people like me, who point this out!”
Via: Why John J. Mearsheimer is Right - R. Kaplan
"...we’re too close to an astounding point for me to leave it unspoken. At that 2.3% growth rate, we would be using energy at a rate corresponding to the total solar input striking Earth in a little over 400 years. We would consume something comparable to the entire sun in 1400 years from now. By 2500 years, we would use energy at the rate of the entire Milky Way galaxy—100 billion stars! I think you can see the absurdity of continued energy growth. 2500 years is not that long, from a historical perspective. We know what we were doing 2500 years ago. I think I know what we’re not going to be doing 2500 years hence."
Via: Exponential Economist Meets Finite Physicist - Tom Murphy