Theory of Demand

This is an expository article. It states and explains the Marshalian theory of demand based on the assumption of cardinal utility. Various ambiguities in Marshall's formulation are discussed. On this background is then described the new demand theory based on in-difference curves. Here also several ambiguities are discussed and explained. The income and substitution effects of a price change are explained in a different way from that of Hicks and why Hick's exposition in this connection is not satisfactory is discussed.