One of the earliest and most famous definitions of economics was that of Thomas Carlyle who in the early 19th century termed it the "dismal science." What Carlyle had noticed was the anti-utopian implications of economics. Many utopians, people who believe that a society of abundance without conflict is possible, believe that good results come from good motives and good motives lead to good results. Economists have always disputed this, and it was the forceful statement of this disagreement by early economists such as Thomas Malthus and David Ricardo which Carlyle reacted to.
Another early definition, one which is perhaps more useful, is that of English economist W. Stanley Jevons who, in the late 19th century, wrote that economics was "the mechanics of utility and self interest." One can think of economics as the social science which explores the results of people acting on the basis of self-interest. There is more to man than self-interest, and the other social sciences--such as psychology, sociology, anthropology, and political science--attempt to tell us about those other dimensions of man. As you read further into these pages, you will see that the assumption of self-interest, that a person tries to do the best for himself with what he has, underlies virtually all of economic theory.
At the turn of the century, Alfred Marshall's Principles of economics was the most influential textbook in economics. Marshall defined economics as:
"a study of mankind in the ordinary business of life; it examines that part of individual and social action which is most closely connected with the attainment and with the use of the material requisites of wellbeing. Thus it is on one side a study of wealth; and on the other, and more important side, a part of the study of man."
Many other books of the period included in their definitions something about the "study of exchange and production." Definitions of this sort emphasize that the topics with which economics is most closely identified concern those processes involved in meeting man's material needs. Economists today do not use these definitions because the boundaries of economics have expanded since Marshall. Economists do more than study exchange and production, though exchange remains at the heart of economics.
Most contemporary definitions of economics involve the notions of choice and scarcity. Perhaps the earliest of these is by Lionell Robbins in 1935: "economics is a science which studies human behavior as a relationship between ends and scarce means which have alternative uses." Virtually all textbooks have definitions which are derived from this definition. Though the exact wording differs from author to author, the standard definition is something like this:
"economics is the social science which examines how people choose to use limited or scarce resources in attempting to satisfy their unlimited wants."