The Market
From the just price to the invisible hand and beyond — how we came to trust prices to coordinate the world.
Each star is a thinker or work; solid lines draw the constellation of a school, dashed threads the passage of ideas between eras.
Select any point on the timeline to read about it.
All entries by era
The Market 400 BCE – 2030 CE
From the just price to the invisible hand and beyond — how we came to trust prices to coordinate the world.
- 350 BCE
Aristotle, Nicomachean Ethics & Politics. Aristotle treats exchange as a matter of justice, seeking proportionate reciprocity between traders, and distinguishes honest household provisioning from money-making for its own sake, which he distrusts. Interest-bearing loans he condemns outright — a suspicion of the market's autonomy that endures for centuries.
- 1265 CE
Thomas Aquinas, Summa Theologiae. Aquinas develops the medieval doctrine of the just price, condemning fraud and, following Aristotle, usury as a sin. Yet he concedes that scarcity and a seller's need legitimately move prices — the beginnings of an idea that value depends on circumstance, not fiat.
- 1776 CE
Adam Smith, The Wealth of Nations. Smith argues that individuals pursuing their own gain are led 'as if by an invisible hand' to promote an end that was no part of their intention — the wealth of the whole society. Division of labour and free exchange, not benevolence, become the engine of prosperity.
- 1817 CE
David Ricardo, Principles of Political Economy. Ricardo shows that two countries gain from trade even if one is more efficient at everything, so long as they specialise where their relative cost is lowest. Comparative advantage turns the market into an argument for global exchange that still frames trade debates today.
- 1867 CE
Karl Marx, Capital. Marx argues that behind the fair-looking exchange of the market lies the extraction of surplus value from labour, and that commodity exchange masks real social relations as 'commodity fetishism'. The market is not neutral coordination but a historically specific system destined, he holds, for crisis.
- 1871 CE
Jevons, Menger & Walras, marginalism. Almost simultaneously, Jevons, Menger and Walras locate value not in labour or cost but in marginal utility — the worth of the last unit consumed. This 'marginal revolution' recasts economics around individual choice and lays the foundations of modern supply-and-demand analysis.
- 1890 CE
Alfred Marshall, Principles of Economics. Marshall unites cost and utility with his famous image of supply and demand as the two blades of a scissors, neither alone determining price. His crossing curves become the single most recognisable diagram in economics and the market's defining picture.
- 1936 CE
J. M. Keynes, General Theory. Against the classical faith that markets automatically reach full employment, Keynes argues that deficient aggregate demand can leave economies stuck in slump. His work justifies active fiscal and monetary policy and dominates postwar economics for decades.
- 1945 CE
Hayek, 'The Use of Knowledge in Society'. Hayek argues that the knowledge needed to run an economy is dispersed among millions of people and can never be centralised, but prices summarise it and let people coordinate without anyone commanding the whole. The market becomes, above all, a mechanism for processing information — the decisive case against central planning.
- 1970 CE
Akerlof, 'The Market for Lemons'. Akerlof shows that when sellers know more than buyers — as with used cars, the 'lemons' — good goods can be driven out and the market can unravel altogether. His paper launches the economics of information and maps the systematic ways real markets fall short of the textbook ideal.
The milestones
c. 350 BCE
Aristotle, Nicomachean Ethics & Politics
Exchange as reciprocal justice
Aristotle treats exchange as a matter of justice, seeking proportionate reciprocity between traders, and distinguishes honest household provisioning from money-making for its own sake, which he distrusts. Interest-bearing loans he condemns outright — a suspicion of the market's autonomy that endures for centuries.
c. 1265
Thomas Aquinas, Summa Theologiae
The doctrine of the just price
Aquinas develops the medieval doctrine of the just price, condemning fraud and, following Aristotle, usury as a sin. Yet he concedes that scarcity and a seller's need legitimately move prices — the beginnings of an idea that value depends on circumstance, not fiat.
1776
Adam Smith, The Wealth of Nations
The invisible hand
Smith argues that individuals pursuing their own gain are led 'as if by an invisible hand' to promote an end that was no part of their intention — the wealth of the whole society. Division of labour and free exchange, not benevolence, become the engine of prosperity.
1817
David Ricardo, Principles of Political Economy
Comparative advantage
Ricardo shows that two countries gain from trade even if one is more efficient at everything, so long as they specialise where their relative cost is lowest. Comparative advantage turns the market into an argument for global exchange that still frames trade debates today.
1867
Karl Marx, Capital
The market as exploitation
Marx argues that behind the fair-looking exchange of the market lies the extraction of surplus value from labour, and that commodity exchange masks real social relations as 'commodity fetishism'. The market is not neutral coordination but a historically specific system destined, he holds, for crisis.
1871
Jevons, Menger & Walras, marginalism
Value at the margin
Almost simultaneously, Jevons, Menger and Walras locate value not in labour or cost but in marginal utility — the worth of the last unit consumed. This 'marginal revolution' recasts economics around individual choice and lays the foundations of modern supply-and-demand analysis.
1890
Alfred Marshall, Principles of Economics
The scissors of supply and demand
Marshall unites cost and utility with his famous image of supply and demand as the two blades of a scissors, neither alone determining price. His crossing curves become the single most recognisable diagram in economics and the market's defining picture.
1936
J. M. Keynes, General Theory
Markets can fail to clear
Against the classical faith that markets automatically reach full employment, Keynes argues that deficient aggregate demand can leave economies stuck in slump. His work justifies active fiscal and monetary policy and dominates postwar economics for decades.
1945
Hayek, 'The Use of Knowledge in Society'
The market as an information system
Hayek argues that the knowledge needed to run an economy is dispersed among millions of people and can never be centralised, but prices summarise it and let people coordinate without anyone commanding the whole. The market becomes, above all, a mechanism for processing information — the decisive case against central planning.
1970
Akerlof, 'The Market for Lemons'
When information asymmetry breaks the market
Akerlof shows that when sellers know more than buyers — as with used cars, the 'lemons' — good goods can be driven out and the market can unravel altogether. His paper launches the economics of information and maps the systematic ways real markets fall short of the textbook ideal.