We have learned to be citizens of the world, members of the human community.

I am not an Athenian nor a Greek, but a citizen of the world.

Mankind is a single body and each nation a part of that body. We must never say "What does it matter to me if some part of the world is ailing?" If there is such an illness, we must concern ourselves with it as though we were having that illness.

In a recent survey of Millennials around the world asking what most defines our identity, the most popular wasn't nationality, ethnicity or religion. It was "citizen of the world." That's a big deal. Every generation expands the circle of people we consider one of us. And in our generation, that now includes the whole world. This is the struggle of our time. The forces of freedom, openness, and global community against the forces of authoritarianism, isolationism, and nationalism - forces for the flow of knowledge, trade, and immigration, against those who would slow them down.

The real problem is that through our scientific genius we've made of the world a neighborhood, but through our moral and spiritual genius we've failed to make of it a brotherhood.

A dark old world was devastated by wars between conflicting religions. A dark modern world faces wars between conflicting economic and political fanaticisms in which are intertwined race hatreds.