The great question for our time is, how to make sure that the continuing scientific revolution brings benefits to everybody rather than widening the gap between rich and poor. To lift up poor countries, and poor people in rich countries, from poverty, to give them a chance of a decent life, technology is not enough. Technology must be guided and driven by ethics if it is to do more than provide new toys for the rich.
The progress of science requires the growth of understanding in both directions, downward from the whole to the parts and upward from the parts to the whole. A reductionist philosophy, arbitrarily proclaiming that the growth of understanding must go only in one direction, makes no scientific sense. Indeed, dogmatic philosophical beliefs of any kind have no place in science.
In desperation I asked Fermi whether he was not impressed by the agreement between our calculated numbers and his measured numbers. He replied, "How many arbitrary parameters did you use for your calculations?" I thought for a moment about our cut-off procedures and said, "Four." He said, "I remember my friend Johnny Von Neumann used to say, with four parameters I can fit an elephant, and with five I can make him wiggle his trunk." With that, the conversation was over.
It is characteristic of all deep human problems that they are not to be approached without some humor and some bewilderment.
I am neither a saint nor a theologian. To me, good works are more important than theology. We all know that religion has been historically, and still is today, a cause of great evil as well as great good in human affairs. We have seen terrible wars and terrible persecutions conducted in the name of religion. We have also seen large numbers of people inspired by religion to lives of heroic virtue, bringing education and medical care to the poor, helping to abolish slavery and spread peace among nations. Religion amplifies the good and evil tendencies of individual souls.
Scientists and business leaders who care about social justice should join forces with environmental and religious organizations to give political clout to ethics.
There is no easy solution to the conflict between fundamentalist Christian dogma and the facts of biological evolution. I am not saying that the conflict could have been altogether avoided. I am saying only that the conflict was made more bitter and more damaging, both to religion and to science, by the dogmatic and self-righteousness of scientists. What was needed was a little more human charity, a little more willingness to listen rather than to lay down the law, a little more humility. Scientists stand in need of these Christian virtues just as much as preachers do.
The common root of modern science and Christian theology was Greek philosophy. The historical accident that caused the Christian religion to become heavily theological was the fact that Jesus was born in the Eastern part of the Roman Empire at the time when the prevailing culture was profoundly Greek.
I have felt it myself. The glitter of nuclear weapons. It is irresistible if you come to them as a scientist. To feel it's there in your hands, to release this energy that fuels the stars, to let it do your bidding. To perform these miracles, to lift a million tons of rock into the sky. It is something that gives people an illusion of illimitable power, and it is, in some ways, responsible for all our troubles, this, what you might call technical arrogance, that overcomes people when they see what they can do with their minds.
All through our history, we have been changing the world with our technology. Our technology has been of two kinds, green and grey. Green technology is seeds and plants, gardens and vineyards and orchards, domesticated horses and cows and pigs, milk and cheese, leather and wool. Grey technology is bronze and steel, spears and guns, coal and oil and electricity, automobiles and airplanes and rockets, telephones and computers. Civilization began with green technology, with agriculture and animal-breeding, ten thousand years ago. Then, beginning about three thousand years ago, grey technology became dominant, with mining and metallurgy and machinery. For the last five hundred years, grey technology has been racing ahead and has given birth to the modern world of cities and factories and supermarkets.