Researchers and agencies collect reams of objective data and authors publish volumes of subjective prose in attempts to explain what is meant by environmental quality. Still, we have no universally recognized methods for combining our quantitative measures with our qualitative concepts of environ- ment. Not all of our environmental goals should be reduced to mere numbers, but many of them can be; and without these quantitative terms, we have no way of defining our present position nor of selecting positions we wish to attain on any logically established scale of environmen tal values. Stated...