The spiritual sense of our place in nature... can be traced to the origins of human civilization... The last vestige of organized goddess worship was eliminated by Christianity.

The fate of mankind, as well as religion, depends on the emergence of a new faith in the future. Armed with such a faith, we might find it possible to resanctify the earth.

We have to abandon the conceit that isolated personal actions are going to solve this crisis. Our policies have to shift.

I had a detailed plan for my life, but it turned out life had a completely different plan for me. And I feel joy that I have work that feels like it justifies pouring everything I have into it. I never have fallen prey to the illusion that there's any job with as much ability to influence the future as that of President of the United States, but I do feel grateful that I found other ways to do work that serves the public interest.

The interior of the earth is extremely hot – several million degrees.

Population growth is straining the Earth's resources to the breaking point, and educating girls is the single most important factor in stabilizing that. That, plus helping women gain political and economic power and safeguarding their reproductive rights.

It seems an easy choice - sacrifice the tree for a human life - until one learns that three trees must be destroyed for each patient treated. Suddenly we must confront some tough questions. How important are the medical needs of future generations?