Religious beliefs evolved by group-selection, tribe competing against tribe, and the illogic of religions is not a weakness but their essential strength.

You are capable of more than you know. Choose a goal that seems right for you and strive to be the best, however hard the path. Aim high. Behave honorably. Prepare to be alone at times, and to endure failure. Persist! The world needs all you can give.

Each of these [bacterial] species are masterpieces of evolution. Each has persisted for thousands to millions of years. Each is exquisitely adapted to the environment in which it lives, interlocked with other species to form ecosystems upon which our own lives depend in ways we have not begun even to imagine.

Man's destiny is to know, if only because societies with knowledge culturally dominate societies that lack it. Luddites and anti-intellectuals do not master the differential equations of thermodynamics or the biochemical cures of illness. They stay in thatched huts and die young.

One planet, one experiment.

The two major challenges for the 21st century are to improve the economic situation of the majority and save as much of the planet as we can.

The great challenge of the twenty-first century is to raise people everywhere to a decent standard of living while preserving as much of the rest of life as possible.