who came up with the law of diminishing marginal utility
Marginal utility Carl Menger presented the theory in Grundsätze der Volkswirtschaftslehre (translated as Principles of Economics) in 1871. Menger's presentation is peculiarly notable on two points. First, he took special pains to explain why individuals should be expected to rank possible uses and then to use marginal utility to decide amongst trade-offs. (For this reason, Menger and his followers are sometimes called “the Psychological School”, though they are more frequently known as “the Austrian School” or as “the Vienna School”.) Second, while his illustrative examples present utility as quantified, his essential assumptions do not.[11] (Menger in fact crossed-out the numerical tables in his own copy of the published Grundsätze.[39]) Menger also developed the law of diminishing marginal utility.[14] Menger's work found a significant and appreciative audience.
Economics Jean-Baptiste Say (1803), distinguishing the subject from its public-policy uses, defines it as the science of production, distribution, and consumption of wealth.[20] On the satirical side, Thomas Carlyle (1849) coined "the dismal science" as an epithet for classical economics, in this context, commonly linked to the pessimistic analysis of Malthus (1798).[21] John Stuart Mill (1844) defines the subject in a social context as: