For the past several days, there has been widespread debate about whether Donald Trump’s extreme rhetoric is to blame for the mail bombs sent to high-profile Democratic critics of the president. Now, there will likely be an even bigger debate about whether he is responsible for the horrific murders at Pittsburgh’s Tree of Life synagogue.

Especially in the more recent case, the answer is less simple than it might seem at first glance. For one thing, it is inherently difficult to ascribe the actions of ideological fanatics to any one underlying cause. Human behavior is influenced by many factors, and when it falls so far outside the mainstream that it involves murderous intent and deadly violence, the actor’s sole motivation cannot be reduced to his political beliefs alone.

For another, it’s clear that the suspect in the mail bombings was a fan of the president’s, and that he chose political targets—prominent Democrats and journalists—whom the president and his allies have regularly demonized.

But the emerging press reports about the synagogue shooter indicate that his political beliefs were more complicated. He was a staunch anti-Semite. A few hours before he set out to kill as many Jews as he could, he echoed a vile conspiracy theory that blames George Soros for most of America’s evils—the same conspiracy that the president himself validated as recently as Friday. And yet, unlike the man suspected of manufacturing the mail bombs, one of which was sent to Soros, the Pittsburgh suspect does not appear to have been a fan of the president’s.

Rather, he regarded Trump as a “globalist” who had sold out to the Jewish world conspiracy.

Most likely, we’ll never know whether one fewer inflammatory tweet or one more conciliatory speech from the president might have averted the massacre in Pittsburgh. And yet, Trump’s reckless determination to crank the temperature of American politics up to the highest possible setting was likely a contributing factor. And that’s why the best analogy for understanding Trump’s responsibility for the rising tides of civic violence in our country may hail from the world of science.

Scientists cannot definitively determine whether any one particular storm is caused by climate change. But they know that the frequency and intensity of extreme weather events have increased due to global warming. In the same way, it is impossible to definitively ascribe any one particular hate crime or terrorist attack to extreme political rhetoric. But it is clear that the kind of violent and dehumanizing language that is the hallmark of Trump’s political style is likely to increase the number of such crimes. That is enough to make the president morally culpable for an overall increase in civic strife, even if we cannot know whether he is causally responsible for this or that specific act of violence.

The latest bout of deadly anti-Semitic violence should, then, remind us that words have consequences. It should also remind us that we have, for far too long, taken anti-Semitic words rather too lightly.

Even before Donald Trump poisoned our public discourse, Jews in the United States faced an elevated risk of hate crime. In 2015, for example, Jews were as likely as black Americans to experience assault or intimidation on a per capita basis; they were also at least five times more likely to become the victims of vandalism. And yet, the violent effects of anti-Semitic rhetoric are rarely taken as seriously in public discourse as other forms of prejudice—and its perpetrators are often treated with surprising gentleness.

There can be absolutely no equivalence between actual violence and a lack of civility.

One reason for that is the notion that Jews cannot be victims of bigotry in the way that other minority groups are, because most Jews are white. As Saturday’s events in Pittsburgh tragically demonstrate, that is simply not the case. But this moral confusion about Jews—that their white skin and relative affluence protect them from hatred—has paved the way for an astounding amount of tolerance toward the anti-Semitically intolerant.

Unlike Trump, for example, Louis Farrakhan has openly called Jews termites and likened them to poison. And yet, it’s still possible to be both a friend of Farrakhan’s and admired by many progressive Americans. Farrakhan’s political influence may be minimal among mainstream Democrats, but Rep. Danny Davis and Women’s March organizer Tamika Mallory defended him earlier this year; after meeting Farrakhan two years ago, Marc Lamont Hill, a popular CNN analyst and professor at Temple University, boasted on Instagram that he had had “an amazing time of learning, listening [and] laughing” with one of the country’s most infamous anti-Semites. After the horrific slaughter in Pittsburgh, this must finally change.

Over the past few days, a depressingly large number of conservative luminaries have drawn comparisons between left-wing protestors who shout at senior Trump administration officials in public and right-wing extremists who resort to mail bombs or (now) mass shootings. This attempt to draw a moral equivalence between two vastly different phenomena would have the virtue of absurdist humor if it didn’t also suffer from the vice of reckless depravity. There can be absolutely no equivalence between actual violence and a lack of civility. Nor are both sides equally at fault for the dangerous divisions the country now faces.

And yet, the recent attacks should also help to explain why the demise of civility is, to put it mildly, not a cause for celebration. To remain peaceful, democracies depend on the willingness of political partisans to settle their differences within the rules prescribed by existing institutions and to extend each other a minimum degree of mutual toleration. When that willingness wanes, and a growing number of citizens gives up on accomplishing their goals through institutional means, political violence inevitably rises.

It is clear that Donald Trump bears the main culpability for destroying whatever norms of civility we still retained a few years ago. It is unfortunately less clear that responding in kind offers a realistic path for getting us out of this mess. If we proudly declare civility to be dead and start to escalate conflict ourselves, we run three big risks: First, we are likely to alienate many of the voters we need to oust Donald Trump from office. Second, we give far-right extremists cover by creating the (wrong!) impression that both sides are similarly willing to use violence. And third, we further erode trust in the institutions we will need after Trump is defeated, in order to break the cycle of escalating civic strife.

For the next two years, we won’t be able to get rid of the bully in the White House who does so much to incite hatred from his pulpit. But thankfully, we still retain the freedom to fight him in peaceful—and, yes, civil—ways: We can make sure that we vote in the midterms and convince as many others as we can to do the same. We can become more consistent in condemning racism and anti-Semitism, even when it comes from our own side. We can marshal our anger to fight the extremists in the political institutions, in public debates—and in peaceful protests. And when we find ourselves face-to-face with one of the people complicit in poisoning our public debate, we can calmly and forcefully explain why they are morally responsible for spilling the blood of our fellow citizens.

I know: These responses aren’t remotely equal to our anger. At times, it would feel so much more satisfying to shout or perhaps even to punch. But these peaceful tactics give us the best chance of convincing our fellow citizens that it is Trump who’s threatening American values—and of achieving a country in which political violence is a rare aberration rather than a daily occurrence.