We often feel that a clever aphorism captures a truth that would require pages to defend in any other way.

Knowing there is a world that will outlive you, there are people whose well-being depends on how you live your life, affects the way you live your life, whether or not you directly experience those effects. You want to be the kind of person who has the larger view, who takes other people's interests into account, who's dedicated to the principles that you can justify, like justice, knowledge, truth, beauty and morality.

People have long assumed that violence is necessary for political change. Rulers never cede power voluntarily, the argument goes, so progressives have no choice but to contemplate the use of force to bring about a better world, mindful of the trade-off between a small amount of violence now and acceptance of an unjust status quo indefinitely.

Academics lack perspective. In a debate on whether the world is round, they would argue, 'No,' because it's an oblate spheroid. They suffer from 'the curse of knowledge': the inability to imagine what it's like not to know something that they know.

Broadly speaking, the Southern and Western desert and mountain states will vote for the candidate who endorses an aggressive military, a role for religion in public life, laissez-faire economic policies, private ownership of guns and relaxed conditions for using them, less regulation and taxation, and a valorization of the traditional family.

Being smarter gives you a tailwind throughout life. People who are more intelligent earn more, live longer, get divorced less, are less likely to get addicted to alcohol and tobacco, and their children live longer.

For all the tribulations in our lives, for all the troubles that remain in the world, the decline of violence is an accomplishment that we can savor - and an impetus to cherish the forces of civilization and enlightenment that made it possible.