The main fuel to speed the world's progress is our stock of knowledge, and the brake is our lack of imagination.

Because we can expect future generations to be richer than we are, no matter what we do about resources, asking us to refrain from using resources now so that future generations can have them later is like asking the poor to make gifts to the rich.

There is only one important resource which has shown a trend of increasing scarcity rather than increasing abundance. That resource is the most important of all—human beings. . . . [An] increase in the price of peoples’ services is a clear indication that people are becoming more scarce even though there are more of us.

Energy is the master resource, because energy enables us to convert one material into another. As natural scientists continue to learn more about the transformation of materials from one form to another with the aid of energy, energy will be even more important.

We now have in our hands—really, in our libraries—the technology to feed, clothe, and supply energy to an ever-growing population for the next seven billion years.

This is my long-run forecast in brief: The material conditions of life will continue to get better for most people, in most countries, most of the time, indefinitely. Within a century or two, all nations and most of humanity will be at or above today's Western living standards. I also speculate, however, that many people will continue to think and say that the conditions of life are getting worse.

Adding more people causes problems. But people are also the means to solve these problems. The main fuel to speed the world’s progress is our stock of knowledge; the brakes are our lack of imagination and unsound social regulations of these activities. The ultimate resource is people—especially skilled, spirited, and hopeful young people endowed with liberty—who will exert their wills and imaginations for their own benefits, and so inevitably they will benefit the rest of us as well.