As the chemist and geographer Daniel B. Luten observed on the eve of the famous 1980 Julian Simon-Paul Ehrlich wager, since the late 18th century “the question of limits to growth and optimism and pessimism regarding the human prospect [has been] debated without consensus” while interest in the issue has “waxed and waned more times than can be counted.” The British economist Alfred Marshall commented more generally almost a century earlier that if the “study of the growth of population is often spoken of as though it were a modern one,” it has “in a more or less vague form…occupied the attention of thoughtful men in all ages of the world.” This perspective was shared by economists Harold J. Barnett and Chandler Morse, who wrote that “Man’s relationship to the natural environment, and nature’s influence upon the course and quality of human life, are among the oldest topics of speculation of which we are aware. Myth, folktale, and fable; custom, institution, and law; philosophy, science, and technology—all, as far back as records extend, attest to an abiding interest in these concerns.”