Liberal certitudes continue to dissolve, the most recent solvent being a robust new defense of a 1905 Supreme Court decision that liberals have long reviled — and misrepresented. To understand why the court correctly decided Lochner v. New York and why this is relevant to current arguments, read David E. Bernstein’s “Rehabilitating Lochner: Defending Individual Rights against Progressive Reform.”

Since the New Deal, courts have stopped defending liberty of contract and other unenumerated rights grounded in America’s natural rights tradition. These are referred to by the Ninth Amendment, which explicitly protects unenumerated rights “retained by the people,” and by the “privileges or immunities” and “liberty” cited in the 14th Amendment. Progressivism, Bernstein argues, is hostile to America’s premise that individuals possess rights that preexist government and are not fully enumerated in the Constitution. This doctrine stands athwart liberalism’s aspiration to erase constitutional limits on government’s regulatory powers.

An 1895 New York law limited bakery employees to working 10 hours a day and 60 hours a week. Ostensibly, this was health and safety legislation; actually, it was rent-seeking by large, unionized bakeries and the unions. Corporate bakeries supported the legislation, which burdened their small, family-owned competitors. The bakers union hoped to suppress the small, non-unionized bakeries that depended on flexible work schedules.

One such was owned by Joseph Lochner, who challenged the law, prevailing in the Supreme Court, 5 to 4. The majority said “clean and wholesome bread” does not depend on limiting workers’ hours: Workers are “in no sense wards of the state,” and there is no evidence that baking is an especially unhealthful profession, so the law was an unconstitutional “interference” with an unenumerated right of individuals, the liberty of contract.

The main dissent radiated progressivism’s statism and paternalism: Government may limit working hours lest workers damage their “physical and mental capacity to serve the State, and to provide for those dependent upon them.” In another dissent, ultimately famous and hugely influential, Oliver Wendell Holmes, whose judicial restraint often expressed his dogmatic majoritarianism, defended “the right of a majority to embody their opinions in law.” He said liberty should not be construed “to prevent the natural outcome of a dominant opinion.”

Princeton’s president, Woodrow Wilson, agreed, dismissing “the inalienable rights of the individual” as “nonsense” inimical to government’s ability to efficiently work its progressive will. So much for the idea that one of the Constitution’s primary purposes is the protection of individual rights against majority tyranny.

Progressives celebrated Holmes’s gift to government of almost untrammeled police powers. He said courts should defer to economic regulations because the Constitution does not “embody a particular economic theory.” Thus began liberals’ distortion of Lochner as expressing the court’s commitment to laissez-faire doctrine.

Actually, the decision flowed from bedrock American doctrine: The individual possesses inalienable rights — here, liberty of contract — that cannot be legislated away for casual or disreputable reasons. Hence progressives’ frequent denunciations of “individualism” — allowing individual rights, particularly those of property and contract, to impede the administrative state’s regulation of society, immune from judicial review.

Bernstein recounts how liberty of contract was invoked — sometimes successfully, usually not — against legislatures that declared women unsuited to practice law or limited women to working fewer hours than men. Labor unions representing male bartenders produced Michigan’s law banning female bartenders.

Other laws favored by progressives defended family men from “destructive” competition with female workers who, by working outside the home, “weakened the race.” A feminist correctly argued, on Lochner’s natural rights grounds, that restricting women’s liberty of contract regarding hours of work “amounts to confiscation of whatever amount would have been earned during the forbidden hours.” In 1926, Georgia’s Supreme Court cited Lochner’s affirmation of liberty of contract to overturn a law prohibiting black barbers from cutting white children’s hair.

Lochner was successfully invoked against laws enforcing residential segregation by race but unsuccessfully against laws banning miscegenation. Many progressives supported such laws as enabling government to regulate racial friction. And after the triumph of progressive jurisprudence during the New Deal, courts capitulated to legislatures in the name of democratic deference to what Holmes called the “dominant opinion.” It became mostly futile to invoke Lochner’s logic — that individual rights often trump government’s powers to boss people around.

Long execrated by most law professors, Lochner is the liberals’ least favorite decision because its premises pose a threat to their aspiration, which is to provide an emancipation proclamation for regulatory government. The rehabilitation of Lochner is another step in the disarmament of such thinking.