Alfred Marshall defines economics as “the study of mankind in ordinary business of life”, it is clear from the above definition that it does not study who lives aloof in some desert or jungle, but a man who lives in society. Even in society the man is not studied individually. Economics is concerned with the aggregate behavior of the message. For instance, if a man goes to the market and buys more of those goods which have high prices and less of those goods which have high prices and less of those goods which have low prices. It would not conclude from this fact that man always buys more units of goods at higher prices and less at lower prices. The economists will see the aggregate behavior of the masses and thus will formulate economic laws. The aggregate behavior of the human being is that other things being equal buy more when the market is cheap and buy less when they are dear. So is the case with other laws of economics, thus we conclude that economics is a social science.