Economists commonly prefer to distinguish normative economics ("what ought to be" in economic matters) from positive economics ("what is"). Many normative (value) judgments, however, are held conditionally, to be given up if facts or knowledge of facts changes, so that a change of values may be purely scientific.Stanley Wong (1987). "Positive economics," The New Palgrave: A Dictionary of Economics, v. 3, p. 21. On the other hand, welfare economist Amartya Sen distinguishes basic (normative) judgements, which do not depend on such knowledge, from nonbasic judgments, which do. He said, "no judgments are demonstrably basic" while some value judgments may be shown to be nonbasic. This leaves open the possibility of fruitful scientific discussion of value judgments.Amartya K. Sen (1970), Collective Choice and Social Welfare, pp. 61, 63-64).
