The paradox of value (also known as the diamond–water paradox) is the contradiction that, although water is on the whole more useful, in terms of survival, than diamonds, diamonds command a higher price in the market. The philosopher Adam Smith is often considered to be the classic presenter of this paradox, although it had already appeared as early as Plato's Euthydemus. Nicolaus Copernicus, John Locke, John Law and others had previously tried to explain the disparity. Labor theory of value In a passage of Adam Smith's An Inquiry into the Nature and Causes of the Wealth of Nations, he discusses the concepts of value in use and value in exchange, and notices how they tend to differ: Furthermore, he explained the value in exchange as being determined by labor: Hence, Smith denied a necessary relationship between price and utility. Price on this view was related to a factor of production (namely, labor) and not to the point of view of the consumer. Proponents of the labor theory of value see that as the resolution of the paradox. Marginalism The theory of marginal utility, which is based on the subjective theory of value, says that the price at which an object trades in the market is determined neither by how much labor was exerted in its production nor on how useful it is on the whole. Rather, its price is determined by its marginal utility. The marginal utility of a good is derived from its most important use to a person. So, if someone possesses a good, they will use it to satisfy some need or want, starting with the one that takes highest priority. Eugen von Böhm-Bawerk illustrated this with the example of a farmer having five sacks of grain. With the first, he will make bread to survive. With the second, he will make more bread, in order to be strong enough to work. With the next, he will feed his farm animals. The next is used to make whisky, and the last one he feeds to the pigeons. If one of those bags is stolen, he will not reduce each of those activities by one-fifth; instead, he will stop feeding the pigeons. So, the value of the fifth bag of grain is equal to the satisfaction he gets from feeding the pigeons. If he sells that bag and neglects the pigeons, his least productive use of the remaining