The King's 28 letters have been described by scholars as the world's best alphabet and the most scientific system of writing.

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

Forced to choose between limiting population or trying to increase food production, we chose the latter and ended up with starvation, warfare, and tyranny.

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.

AIDS and malaria and TB are national security issues. A worldwide program to get a start on dealing with these issues would cost about $25 billion... It's, what, a few months in Iraq.

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

Biology is the science. Evolution is the concept that makes biology unique.

Technology has to be invented or adopted.

Rhino-mounted Bantu shock troops could have overthrown the Roman Empire. It never happened.

Human societies vary in lots of independent factors affecting their openness to innovation.

Why did human development proceed at such different rates on different continents for the last 13,000 years?

There's always one more way to do things and that's your way, and you have a right to try it at least once.

It’s as if everyone got cancer the day I was diagnosed, except I’m their tumor.

Drugs are a carnival in hell.

The wise realize that some things are within their control, and most things are not. They learn early on to distinguish between what they can and can't regulate.

Perception is the ability to be conscious of self and that which is other than self. Without thinking about it, a distinction is made between who we are and what we perceive.

Young children give us glimpses of some things that are eternal.

He's (his father Jorge Posada IV) happy for me. He remembers all of my big games. When I hit my first home run in the World Series, he was here, and he cried. It's like I'm living his dream.

Because of the structure of the contemporary American party system, every president is polarizing.

Did you just call me old? I really prefer the word 'experienced'.

With eternity to draw on there could be no reason for hurrying - 'hurry' was not a concept in Martian.