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 two-thirds could not be replicated. Similar problems were found with cancer research.
Or consider economics. Does raising the minimum wage increase unemployment? You can find equally prestigious economists arguing both sides of the question, and it's difficult to tease out the effects of one policy change when many other factors can also affect unemployment.
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?
Some speculated that the crack epidemic's waxing and waning caused the spike and decline in crime. But the timing doesn't really work. Crime began its steep increase in the 1960s, long before the crack craze.
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."
Something else was tickling the back of my mind about the crime rate: 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. Canada, for example, experienced a notable decline in crime during the same period but did not have comparable incarceration rates.
In recent years, some have speculated the proliferation of cellphones may be the reason crime declined so much so fast. Criminals may be warier of committing crimes in the presence of witnesses who can easily call police or snap photos of licenses. Open-air drug markets are less necessary when exchanges can be so easily arranged by cellphone.
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. Oprah Winfrey reflected this thinking (intellectual trends never remain cabined on campuses; they trickle down) when she spoke of "your truth" at the Golden Globes. In other words, you have your truth and I have mine, which means truth doesn't exist. The populist right is feverishly denouncing all uncongenial facts as "fake news."
Truth is not subjective. Water will freeze at 32 degrees Fahrenheit whether we believe it or not. 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.