Marshall definition of Economics was the first to challenge Adam Smith definition. Dr. Alfred Marshall (Born. 26 July 1842, Died 13 July 1924) was the first Economist, who denied the wealth-related definitions of Adam Smith, which was in vogue for a long time, in his two books published in 1890 named Principles of Economics and Economics of Industry, and declared them wrong, and defined it as not the study of human welfare. He gave, ‘Man’ the first place and Wealth’ as secondary and clarified that wealth is for man and man is not for wealth. Wealth is not the ‘End’, it is only a ‘Means’ to attain welfare. He presented the definition of Economics in this manner in his book ‘Economics of Industry’.