Stages of life are artifacts. Adolescence is a useful contrivance, midlife is a moving target, senior citizens are an interest group, and tweenhood is just plain made up.

Folklore used to be passed by word of mouth, from one generation to the next; thats what makes it folklore, as opposed to, say, history, which is written down and stored in an archive.

Nineteenth-century grass-roots populism made twentieth-century progressivism possible.

History is hereditary only in this way: we, all of us, inherit everything, and then we choose what to cherish, what to disavow, and what to do next, which is why it's worth trying to know where things come from.

Republicans were more pro-choice than Democrats up until the late 1980s.

Epidemiologists study patterns in order to combat infection. Stories about epidemics follow patterns, too. Stories arent often deadly, but they can be virulent: spreading fast, weakening resistance, wreaking havoc.

Epidemics follow patterns because diseases follow patterns. Viruses spread; they reproduce; they die.