It invites a search for ultimate causes: why were Europeans, rather than Africans or Native Americans, the ones to end up with guns, the nastiest germs, and steel?

Not until the beginning of the 20th century did Europe's urban populations finally become self-sustaining: before then, constant immigration of healthy peasants from the countryside was necessary to make up for the constant deaths of city dwellers from crowd diseases.

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

The past was still a Golden Age, of ignorance, while the present is an Iron Age of willful bliss.

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.

In the latter case it is often government that organizes the conquest, and religion that justifies it.

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