William Stanley Jevons was a British economist and logician, born in 1835. He is best known for his contributions to the field of economics, particularly for developing the Marginal Utility Theory, which explains how individuals make decisions based on the additional satisfaction gained from consuming one more unit of a good or service. Jevons also emphasized the importance of mathematical methods in economic analysis. In addition to his work in economics, Jevons made significant contributions to logic and philosophy. He authored several influential works, including "The Theory of Political Economy," where he introduced the concept of utility in economic thought. Jevons' ideas laid the groundwork for modern economic theory and influenced later economists, including Alfred Marshall and Leon Walras.