Adam Smith (1723-1790) in his Wealth of Nations deals with the major drivers of the wealth of a country in an analysis that highlights the interrelations among capital, labour and the expansion of markets in the XVIII century. His contribution can be considered a reaction to Mercantilist practices in which protectionism played a decisive role to expand markets. Smith discusses the consequences of the division of labour, exemplifying this question from a pin factory which productivity increases as human beings work on specific tasks. According to Adam Smith, the division of labour has its origin in the propensity of human nature to exchange. Thus, individuals lead to society to well-being while pursuing the maximization of their own interests. Although labour specialization is a key factor for productivity growth, the division of labour could be limited by the extension of the market. In his opinion, labour specialization paves the way for increased production and, therefore, the expansion of the market. In this sense, Smith defended the free operation of markets as a driver of economic growth.
David Ricardo (1772-1823), in his Principles of Political Economy and Taxation, discusses the factors that affect the prices of grain and the connections between land rent and profits. Considering the drivers of the wealth of nations, Ricardo turned out to develop an international trade theory based on comparative advantages that defends the specialization in goods produced at lower costs in a context of free markets. However, Ricardo was ideologically motivated to do so, primarily to prevent developing nations like Portugal from becoming developed and overtaking Great Britain. Ricardo believed that total production would generate an income to be divided into wages, profits and land rent. He returns to the theoretical discussion initiated by Adam Smith on the relative value of goods, their relationship with the amount of labour and advances on the distribution of income.
Karl Marx (1818-1883) makes a re-reading of the British classical economists, most notably David Ricardo and Adam Smith. Marx’s Capital presents an analysis of capitalist society, characterized as a social organization based on an exchange system and the division of labour. In the capitalist system, according to Marx, the free worker sells his labour force and capital is a social relation. The reality of the capital accumulation process, though, is that it is a double movement of production and valorisation. The accumulation process ordinarily produces both use-value and exchange-value. Capitalists are less interested in the commodity-in-itself or the use-value of commodities, but, their interest, as the personification of capital, relies on the expansion of value. Wealth creation is dependent labour power exploited to appropriate surplus value. To Marx, this is the source of profits.
Smith, Ricardo, Marx: Observations on the History of Economic Thought by Claudio Napoleoni (1976)