David Ricardo who accomplished classical economics developed his economic theory assuming that commodities are infinite in his essay “On the Principle of Political Economy And Taxation”, while Adam Smith who is also a classical economist pointed out that commodities were limited because natural resources were finite, in his essay“An Inquiry Into The Nature and Causes of The Wealth of Nations”, The outlook on nature which Smith obtained on his economic theories led two sorts of labour, productive and unproductive. Smith treated of the quality of labour, but, Ricard had his attention only to the quantity of it.