The adoption of agriculture, supposedly our most decisive step toward a better life, was in many ways a catastrophe from which we have never recovered.

One way to explain the complexity and unpredictability of historical systems, despite their ultimate determinacy, is to note that long chains of causation may separate final effects from ultimate causes lying outside the domain of that field of science.

In much of the rest of the world, rich people live in gated communities and drink bottled water. That's increasingly the case in Los Angeles where I come from. So that wealthy people in much of the world are insulated from the consequences of their actions.

Two types of choices seem to me to have been crucial in tipping the outcomes [of the various societies' histories] towards success or failure: long-term planning and willingness to reconsider core values. On reflection we can also recognize the crucial role of these same two choices for the outcomes of our individual lives.

Perhaps our greatest distinction as a species is our capacity, unique among animals, to make counter-evolutionary choices.

The southward advance of native African farmers with Central African crops halted in Natal, beyond which Central African crops couldn't grow - with enormous consequences for the recent history of South Africa.

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