Buried in times of euphoria. Dug up in times of panic. That is the best measure of Keynes’s enduring relevance.

A very recent article in the Guardian about James Graham’s play The Standard of Living reminds us that Keynes was no Excel spreadsheet.

A great lover of art, he belonged to the Bloomsbury Group, that circle of British intellectuals, artists and writers of the early twentieth century that included Virginia Woolf.

In 1918, with the guns still thundering, he crosses war-torn France to attend the sale of Edgar Degas’s studio collection in Paris. He buys works for himself, but also for London’s National Gallery, having secured £20,000 from the Chancellor for the purpose. This is the same man—the most influential economist of the century—who, while chairing the body that would become the Arts Council, leads the British delegation to Bretton Woods in 1944, where the IMF and the World Bank would be born.

Keynes was a committed liberal who believed that wealth should offer time, intelligence and beauty, rather than consume our lives.

The way we use his ideas reveals a strange conception of the state. Its power becomes indispensable when everything threatens to collapse, yet suspect as soon as it is asked to shape the future. Invoking Keynes in an emergency restores a legitimacy that prevention struggles to secure. Yet a society should be able to choose its investments, its protections and its priorities before panic makes those choices for it.

1919: THE PRICE OF PUNISHMENT

At Versailles, he walks out. In The Economic Consequences of the Peace, he does not predict Hitler, but devastation. An exhausted Germany cannot pay; a Europe that punishes without rebuilding is preparing its own ruin.

Weimar’s history would have other causes—hyperinflation, the crash of 1929, mass unemployment, the failure of its elites—but Keynes identifies the central danger. No lasting peace can be built on economic humiliation.

1936: WHEN THE ECONOMY SEIZES UP

In the depths of the Depression, Keynes begins with a simple observation: an economy can collapse not because it lacks machinery or workers, but because it lacks spending.

As uncertainty spreads, businesses stop investing and lay off workers. Households save. Individual caution becomes a mortal sin for society as a whole. Demand falls; supply follows.

This is the revolution of The General Theory: full employment is not automatic, and the state must temporarily support economic activity when the private sector retreats.

His ambition, however, went beyond such emergency intervention, for Keynes envisaged a lasting framework for investment bringing public authority together with private initiative. Full employment must never depend on fluctuations in confidence alone. And society must be able to prepare its future without waiting for the owners of capital to regain their appetite for financing it.

One euro of public spending can then generate more than one euro of economic activity—the multiplier—though there is nothing magical about this relationship. Its effect depends on the pool of unemployed workers, imports, monetary policy and what is being financed.

Hence his barb at Hayek and the advocates of waiting things out: “In the long run we are all dead. Economists set themselves too easy, too useless a task if in tempestuous seasons they can only tell us that when the storm is long past the ocean is flat again.”

1945–1973: PROSPERITY WITH CONDITIONS

The post-war era was not Keynes’s achievement alone: reconstruction, technological catch-up, cheap energy, the baby boom and American hegemony were decisive.

Yet capitalism’s Golden Age rests on a profoundly Keynesian framework: full employment as an objective, public investment, a welfare state, strong trade unions, stable exchange rates, capital controls and regulated finance.

The result, from 1951 to 1973, would be the strongest growth, the lowest unemployment and falling public debt—in short, the near-disappearance of financial crises.

No foolproof formula. Just a compromise: capitalism must be disciplined if it is to remain bearable.

1970–2008: THE CASINO TAKES OVER

The stagflation of the 1970s exposes the limits of the most mechanical prescriptions. Hayek, Friedman and Lucas are right on one point: expectations matter, and inflation can destroy jobs.

The political response, however, would sweep the theory aside, as the liberalisation of capital flows and financial deregulation would run unchecked, with the weakening of labour thrown in for good measure, all in the name of self-regulating markets.

In Keynes’s words: “Speculators may do no harm as bubbles on a steady stream of enterprise. But the position is serious when enterprise becomes the bubble on a whirlpool of speculation. When the capital development of a country becomes a by-product of the activities of a casino, the job is likely to be ill-done.”

In 2008, the casino seizes up.

And then we do what we always do in a panic: bank guarantees, zero interest rates, extraordinary monetary policies, massive deficits.

These interventions do not all belong to the same tradition, for rescuing a bank that has run short of liquidity predates Keynes. John Maynard’s decisive contribution is to show why spending and employment must also be supported when private-sector caution perpetuates the depression. Restoring the flow of credit does not guarantee that businesses will invest or households will spend.

The high priest of anti-Keynesianism, Robert Lucas, would confess: “I guess everyone is a Keynesian in a foxhole.” In other words: when trouble strikes, everyone becomes a Keynesian.

Then 2020 confirms the lesson. Faced with the virus, governments set aside every fiscal taboo to protect incomes, credit and employment. The aim is to prevent cascading bankruptcies and deflation.

He was neither a Marxist nor a prophet. He was an aristocratic liberal who had made it his mission to save capitalism from its internal enemies: instability, inequality, speculation and greed.

His ultimate lesson is not that the state can and must do everything, all the time.

It is that the state must be able to act when the market retreats, when finance threatens the real economy, when private fear becomes a collective catastrophe.

Prevention means sustaining investments that the pursuit of immediate returns discourages, preventing credit from feeding speculation at the expense of production, and reckoning with the losses that inaction will bring. Neglected equipment, lost skills and entrenched unemployment eventually present a bill of their own. Public responsibility means recognising these costs early enough to still avoid them.

We recite Hayek in times of confidence. We call Keynes in an emergency.

It is time to call him—before the crisis reaches breaking point.