It’s good to be modest about our certainty of the truth

Early in George W. Bush’s first term, I was dining with a friend who didn’t agree with my worldview. He challenged my certitude, allowing that he wasn’t sure about many issues. “Don’t you wonder whether you’re right?” he asked. “Well,” I replied, “if I held an incorrect view, I’d change it to the correct one.”

It was a joke, obviously, but I’ve thought of him many times in the intervening years, as my doubts have multiplied about many questions. In that time, I’ve learned — slower than I should have, admittedly — that it’s often impossible to know what the “right” view is. The world is complicated, and our capacity to understand, while glorious, remains limited.

The randomized, controlled study is one of the best tools to test hypotheses, and yet psychology and other fields are currently embroiled in debates over the reliability of published studies. A 2015 examination of 100 psychological studies, published in the magazine Science, found that twothirds could not be replicated.

John Donohue and Steven Levitt caused a minor sensation in 2001 when they theorized that the dramatic drop in crime during the 1990s was traceable to the availability of abortion. Fewer unwanted children after 1973, they argued, had led to fewer criminals. Many challenged the thesis and the data. Some were offended by the implied justification for taking the lives of the unborn. But what did cause the dramatic decline in crime?

At the time, I was completely convinced that Mayor Rudolph Giuliani and “broken windows” policing deserved the credit, and maybe that was right. It seemed intuitively correct that cracking down on quality-of-life crimes, stopping and frisking suspicious individuals and targeting high-crime neighborhoods with extra police would discourage crime. The data were staggering: The crime rate dropped 65 percent during Giuliani’s term.

When New York’s Mayor Bill de Blasio, who campaigned on putting an end to stop and frisk, took office in 2014, I worried that the crime rate would begin to inch back up. But as Kyle Smith acknowledged in National Review, crime has continued to drop in New York: “Four of the five least-murderous years in New York City since 1960 have been in the de Blasio era. Other crime statistics have largely followed suit, with the total number of major crimes down in 2017 by about 6 percent since 2016, which was itself a record-low year.”

Crime dropped everywhere in the United States. It fell in cities that adopted Giuliani-style tough tactics, and it also fell in cities that didn’t.

Perhaps it was incarceration? It’s possible, but not dispositive.

The point of this is not to abandon the scientific method or throw up our hands at the search for truth. In our time, it’s more urgent than ever to rebut those who deny that truth is knowable. The intellectual left has long been under the sway of postmodernism, which denies that objective truth exists. The populist right is feverishly denouncing all uncongenial facts as “fake news.”

Truth is not subjective. But we should be modest about our grasp of the truth, mindful of our limited understanding and our own tendency to reach conclusions first and find evidence second. Maybe this column is right, but I won’t be insulted if you check it.