According to the prosecutors, Weems had falsified “the cash book” of the Coast Guard by entering into an official payroll ledger that he had distributed a month’s wages to employees of two lighthouses when in fact he had not.

Weems, for his part, claimed that he’d made a mistake in the data entry. The court, for its part, found no proof that he’d attempted to defraud the government. But he and the unpaid lighthouse employees and the prosecutors and the judge all happened to live in a different century— the crime occurred in 1904—and in a different country: the Philippines. There and then, the punishment for such an offense was administered by way of an ancient tradition called cadena temporal—“cadena” is the Spanish word for “chain”—and the defendant was sentenced not only to pay a large fine, but also to serve 15 years of “hard and painful labor,” including “the carrying of chains, deprivation of civil rights during imprisonment, and thereafter perpetual disqualification to enjoy political rights.”

Weems appealed the decision to the United States Supreme Court—which was possible only because the Philippine islands were then an American colony. What followed was a landmark 1910 ruling that would help shape a century’s worth of jurisprudence. Justice McKenna, writing for the High Court, said in sum that the punishment didn’t fit the crime. Fifteen years of forced hard labor, bound ankle to wrist in chains, simply wasn’t proportionate to the offense of fudging a payroll ledger.

Such punishment was, the Court ruled, “cruel and unusual,” and therefore violated the Eighth Amendment to the U.S. Constitution.

The Eighth Amendment—at least the proscription against “cruel and unusual punishment”—seems to be the one part of the Bill of Rights that every middle schooler who has faced a parentally imposed grounding—or had their social media privileges revoked—knows by heart. (The full line reads: “Excessive bail shall not be required, nor excessive fines imposed, nor cruel and unusual punishments inflicted.”)

And this precept of justice has a venerable pedigree, tracing back to the Virginia Declaration of Rights of 1776, and before that to the English Bill of Rights in 1689, and before that to English common law, and before that to the lex talionis, and to Leviticus (as framed by the rule, “an eye for an eye”), and to the Code of Hammurabi, and probably to early episodes of The Flintstones.

The precise parameters may still be debated (we continue to squabble over the death penalty, drug laws, and more), but the concept itself is mostly embedded in a common ethic.

I thought of this as I, and the rest of the nation, and the world, heard the wailing of children being separated from their parents at America’s southern border—as we learned of 10-year-olds and toddlers being held in makeshift detention centers, of mothers and fathers not knowing where their children were.

As a society, we can and will argue the parameters of our immigration policy; we should and will no doubt continue to debate the best way to protect our national frontiers. But tearing families apart and incarcerating children for the offense of crossing a border illegally in search of a better life is a punishment both cruel and unusual. It is a punishment wildly disproportionate to the offense.

On Tuesday, U.S. District Judge Dana Sabraw, of the Southern District of California, ordered the federal government to ensure that the 2,000 migrant children who remain separated from their parents are reunited with them within 30 days—or, in the case of children under the age of five, within 14 days. The basis for his order isn’t the Eighth Amendment. Rather, it’s a Constitutional provision known as “due process.” The Trump Administration, said Judge Sabraw, has appeared to violate that tenet in its zealous enforcement of its so-called “zero tolerance” policy at the border.

The “chaotic” way in which family members have been separated and dispersed around the country is sharply counter, he said, to “measured and ordered governance, which is central to the concept of due process enshrined in our Constitution”:

“The practice of separating these families was implemented without any effective system or procedure for (1) tracking the children after they were separated from their parents, (2) enabling communication between the parents and their children after separation, and (3) reuniting the parents and children after the parents are returned to immigration custody following completion of their criminal sentence,” said the judge. “This is a startling reality.”

“Under the present system,” he continued, “migrant children are not accounted for with the same efficiency and accuracy as property.”

It’s not yet clear whether Mr. Trump’s Justice Department will appeal Judge Sabraw’s injunction—which, notably, “does not implicate the Government’s discretionary authority to enforce immigration or other criminal laws, including its decisions to release or detain class members”—only the manner in which the government has done it.

That is much like the ethical zone where “cruel and unusual” lives as well—a place where the differences between right and wrong are separated not by legal lines but rather by our human instinct for fairness.

On Tuesday afternoon, at about the same time that Judge Sabraw was issuing his preliminary injunction, the attorney and justice crusader Bryan Stevenson spoke to the corporate leaders gathered for FORTUNE’s CEO Initiative—a membership organization we launched last year to help companies pursue their own efforts to change the world for the better as they make money for their shareholders, to do well and good at the same time.

Stevenson, who is the founder and Executive Director of the Equal Justice Initiative in Montgomery, Alabama, spoke with extraordinary power and eloquence about what each of us can do to make the world a more just place.

One thing we can do to lessen the cruelty and unfairness of the planet, he said, is simply to bring ourselves closer to it. “When we allow ourselves to be shielded and disconnected from those who are vulnerable and disfavored,” said Stevenson, we allow injustice to fester. What we need instead is proximity to that suffering. “Proximity is a pathway” to justice, and to kindness, and to healthier communities.

The closer we are to one another, in other words, the harder it is to be cruel.

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