Every once in a while something happens that totally shifts the landscape of our perceptions. Every once in a while something profound takes place that makes all our old discussions and ways of understanding move to a new location. Examples abound in history.

Life after Mr. Watt’s steam engine was different forever. The invention of the assembly line catapulted us into an economic world that, for good and ill, shapes our lives even in this moment. Even in the polarized climate in our nation today, we can look with pride at the two-term presidency of the first African-American to hold that office! This doesn’t mean that we are done dealing with the horrors of racism and bigotry — far from it. But the election of Barack Obama is one of those moments. Things have changed.

Each one of us can…