While the nation convulsed through more than two weeks of tumult as the U.S. Senate examined and considered the nomination of Judge Brett Kavanaugh to the Supreme Court, I heard from many people who spoke with absolute certainty. Some were convinced, utterly convinced, that Kavanaugh was falsely accused. Others were just as convinced he was guilty. They saw bright lines and bad motives. Systems of judgment, though — both criminal law and the proceedings involving Kavanaugh — are not black and white. Rather, they’re drawn in grayscale, somewhere on a spectrum between absolutes. And yet we must act on those sometimes subtle gradations.

This is true even where certainty would seem to be most required: in capital cases, where what’s at stake is nothing less than the potential death of an innocent. Yet it turns out that even there, our certainty is unwarranted. Since 1973, more than 160 people sentenced to death have been exonerated of their crimes. We don’t know how many people who were actually executed were innocent. Simply put, sometimes we are wrong even when it’s a matter of life and death rather than a judicial appointment.

I’m a former prosecutor who has trained criminal attorneys for nearly two decades in Texas and Minnesota. One of the difficult things to teach is this lack of bright lines. We all know that criminal cases must be proven beyond a reasonable doubt. But what does this standard mean? Many of our jurisdictions don’t even try to define it. For example, in the federal Seventh Circuit, the model jury instructions define dozens of concepts. But when it comes to “beyond a reasonable doubt,” we find that, simply, “The Committee recommends that no instruction be given defining ‘reasonable doubt.’ ”

Another seeming absolute, invoked often in discussions of the Kavanaugh confirmation, is that Americans are presumed innocent till proven guilty. But even that boundary has been thoroughly trampled and obscured in the interests of practicality. In the federal system, most narcotics defendants face a presumption of detention that can send them to jail pending trial, without bond or bail, regardless of presumed innocence. From behind bars, that bit of poetic language about the cloak of innocence is of little consequence.

For Christians, a warning about the dangerous confluence of outrage and certainty in judgment is right there at the heart of the gospels. At Jesus’ trial, his prosecutor, Caiaphas, was frustrated at the ambiguity of the evidence. Seeking a verdict, he turned to outrage and certainty, tearing at his clothes and crying out, “Why do we still need witnesses?” And, of course, it works.

Because I was a classmate of Judge Kavanaugh’s, I have fielded a lot of questions about events of the last few weeks. I signed a letter supporting him before his initial set of confirmation hearings and have since withdrawn from that letter based on his demeanor at the hearings themselves. I don’t agree with those who say with certainty (and often anger) that Kavanaugh is lying, or that Dr. Christine Blasey Ford was lying in her own testimony. I found her credible and I found his performance disrespectful of a co-equal branch of government, but I don’t know who is lying about the key event at issue. Neither, honestly, do the senators who argued so vociferously on one side or the other.

Yet in a grayscale world, we must make decisions. We do this all the time in criminal law where people lose their freedom, their property and their lives in venues that often refuse to even attempt to define the standard that must be met. People are convicted on the word of a single witness, who may be biased. We do it nonetheless, over and over, to those who are less privileged than Judge Kavanaugh. When Sen. John Kennedy of Louisiana asked Judge Kavanaugh to “swear to God” that he did not sexually assault Dr. Ford, one friend of mine suggested that we would reach racial equity when young black defendants were offered the same option to absolve themselves.

There is an antidote to the cycle of outrage and certainty: humility. If we are to make judgments on who gets to be on a court, who will be locked up and who will live or die based on something less than absolute knowledge of the truth, then we should be humbled by the ultimate uncertainty of what we are doing. Sometimes, after all, we will be wrong, which means that someone will be wrongly denied a judgeship, locked up or killed by the state. A society that accepts the last of these should also accept the first.

As the midterms approach and the Kavanaugh debates remain fresh, there will be loud voices. Hopefully, though, there will also be some calmer ones, devoid of brutal certainty, willing to admit that either way, we might be wrong — and yet we must make a decision nonetheless.

Mark Osler is the Robert and Marion Short Professor of Law at the University of St. Thomas in Minnesota. He is a former Baylor Law School faculty member.