As the preceding dialogue makes clear, arguments over "resources and growth" policy hinge partly on opposing views of man's future access to the earth's finite resources—such as metals and fossil fuels. The "cornucopians" predict that, thanks to man's technical ingenuity, such resources (or adequate substitutes) will prove ample in the long run. The pessimists fear that high development costs and environmental damage preclude an easy transition to an "Age of Substitutability." During the dialogue, most speakers seemed to agree on one point: political barriers to any timely world consensus on "growth" policies are perhaps the biggest immediate problems. Such matters are examined below by Walt W. Rostow, Henry C. Wallich, and Eugene B. Skolnikoff in excerpts from Growth in America (Greenwood Press, 1976), edited by Chester L. Cooper, a former Fellow, and comprising 12 essays prepared for conferences sponsored by the Wilson Center.