Technology causes problems as well as solves problems. Nobody has figured out a way to ensure that, as of tomorrow, technology won't create problems. Technology simply means increased power, which is why we have the global problems we face today.

History as well as life itself is complicated -- neither life nor history is an enterprise for those who seek simplicity and consistency.

I've always been interested in a lot of things, and a lot of things at the same time, and I always tried to explain them to myself. I ask a lot of questions.

Our biggest threat is not an asteroid about to crash into us, something we can do nothing about. Instead, all the major threats facing us today are problems entirely of our own making. And since we made the problems, we can also solve the problems.

What did the last Easter Islander say as he chopped down the last tree? The Easter Islanders didnt have anthropologists.

We're uncomfortable about considering history as a science. It's classified as a social science, which is considered not quite scientific.

Twelve thousand years ago, everybody on earth was a hunter-gatherer; now almost all of us are farmers or else are fed by farmers. The spread of farming from those few sites of origin usually did not occur as a result of the hunter-gatherers' elsewhere adopting farming; hunter-gatherers tend to be conservative.... Instead, farming spread mainly through farmers' outbreeding hunters, developing more potent technology, and then killing the hunters or driving them off of all lands suitable for agriculture.