This week (June 12, to be specific) marked the Adam Smith Institute’s Tax Freedom Day, the symbolic day that British citizens stop working just to pay taxes and get to keep the money you earn. It is a publicity stunt aimed at getting people to notice how much tax they pay. On average, Brits will pay 42 percent of their incomes in taxes in 2017, so tax freedom day falls on the day when we are 42 percent of the way through the year.

The philosopher Julian Baggini last year claimed that this celebration reveals an unreasonable hostility to taxation. Taxes pay for the health service, state schools, the police, pensions and much besides. Instead of celebrating Tax Freedom Day, we should celebrate Social Solidarity Day.

These two days mark the same objective phenomenon – namely, that tax is 42 percent of GDP. But, according to Baggini, calling it Social Solidarity Day has the virtue of avoiding the “tax-as-theft worldview.” We should instead see tax as social solidarity.

Baggini’s view is not unusual. Leftists frequently recommend the “social solidarity” of an expansive welfare state and the taxes required to fund it. On the political Left, the idea...