We live in a time when people who don’t like the news dismiss it as “fake news.” When the idea that seeing isn’t believing emanates not from some Orwellian dystopia, but from the White House; a time when the president’s personal lawyer openly asserts that “truth isn’t truth.”

So, when we’re presented with so many reasons to doubt the truth (or for that matter, doubt the very existence of truth), one natural question to ask is what is the nature of truth?

Patricia Illingworth, a Northeastern professor of philosophy and law, said that we don’t all have to agree on something for it to be true. But we do need to believe that truth exists, particularly within truth-seeking institutions such as higher education, journalism, and the courts system.

“Truth conforms to objective reality,” Illingworth said. “I would distinguish truth from what is agreed upon. For example, there was a time when everyone believed and agreed that the world was flat. Nonetheless, it was not a truth because it did not correspond to reality.”

It’s not unusual for people to have different perspectives, or to have beliefs that diverge from objective reality because they don’t know all the facts. People thought the earth was flat before physics (and satellite images) showed it was round.

What’s dangerous, though, and what Illingworth is concerned about, is a scenario in which truth is presented as purely subjective, or one in which truth simply doesn’t exist and that there is no objective reality.

If truth doesn’t exist, then in principle anything goes, or anyone’s word is as good as anyone else’s word.

Patricia Illingworth, Professor

Earlier this month, President Donald J. Trump said hurricanes Irma and Maria caused “6 to 18 deaths” in Puerto Rico. That statement contrasted wildly with the results of a report commissioned by the governor of Puerto Rico. The report concluded that 3,000 people had died in the U.S. commonwealth as a result of the two hurricanes. As logic would have it, these two things cannot both be true.

Illingworth said that Trump’s assertion of a drastically lower death toll in Puerto Rico appears to be based “on what he heard, or observed when he was in Puerto Rico, as if truth depends only on his subjective experience of the world.

“Mr. Trump’s refusal to publicly acknowledge standard measures of truth in favor of his subjective experience undermines truth, trust, and democracy in the U.S.,” said Illingworth, who is also a Senior Fellow at the Carr Center for Human Rights Policy at the Harvard Kennedy School of Government.

“If truth doesn’t exist, then in principle anything goes, or anyone’s word is as good as anyone else’s word,” she said. “In the absence of truth, or objective reality, people may rely on the subjective beliefs of those in power or on the beliefs of a populous. In either case, democracy is undermined.”

If you can convince people that there is no objective reality, that a single truth doesn’t exist, then you can fill in the void with whatever story benefits you, Illingworth said.

When the president’s lawyer, Rudy Giuliani, said “truth isn’t truth,” he wasn’t saying that people have different perspectives on an issue, or that there are two sides to every story. He was saying that there is no such thing as truth.

In doing so, he undermined the very systems upon which we rely for truth-finding: our court system, scientific discoveries, and the press, Illingworth said.

“Part of the democratic system is deference to or trust in an independent court,” Illingworth said. “He’s denying that, and denying possibility of an honest press or honest science.”

And that is a slippery slope. These are the mechanisms by which we trust other people and society; we have “independent ways of knowing” the truth, Illingworth said. Without them, we turn to groups or authority figures to tell us what’s true.  

“The question for me now is how resilient are these truth-finding systems that are under attack?” Illingworth said. “How resilient is our democracy?”