When he was only 28 years old, Abraham Lincoln delivered an address before the Young Men’s Lyceum of Springfield, Illinois.

The speech included Lincoln’s plea to avoid what he called the “mobocratic spirit.” He warned about an “ill-omen amongst us”–which he identified as, among other things, the “growing disposition to substitute the wild and furious passion, in lieu of the sober judgment of Courts.” 

In fact, the Young Men’s Lyceum speech deals in large part with the issue of passion vs. reason. Lincoln, like the Founders, had a deep insight into human nature, acknowledging that “jealousy, envy, and avarice” are “incident to our nature.” The basest principles of our nature, he said, “were either made to lie dormant, or to become the active agents in the advancement of the noblest of cause — that of establishing and maintaining civil and religious liberty” (meaning they were directed exclusively against the British nation). But at the end of his speech, Lincoln issues this warning:

Passion has helped us; but can do so no more. It will in future be our enemy. Reason, cold, calculating, unimpassioned reason, must furnish all the materials for our future support and defence. Let those materials be moulded into general intelligence, sound morality and, in particular, a reverence for the constitution and laws. This must become America’s “political religion.”

Which brings us to Michigan, where Governor Rick Snyder signed a law declaring that workers will no longer be required to pay union fees as a condition of employment.

National Review offers a summary of the reaction to the new Michigan law: “Democratic legislator Douglas Geiss declared on the floor of the state house: ‘There will be blood. There will be repercussions.’ And indeed there were: Knife-wielding partisans brought down a tent on representatives from the conservative group Americans for Prosperity — women and children among them — and roughed up bystanders. Fox News contributor Steven Crowder was beaten by the same mob, punched repeatedly in the face.” In addition, Teamsters president Jimmy Hoffa declared there would be a “civil war” in Michigan. (A video of some of this can be seen here, courtesy of HotAir.com. And on the left, it’s being said that “getting hit in the face is a hazard of inserting yourself in the middle of an argument between billionaire-funded know-nothing ideologues and people whose livelihoods and stability are being threatened by the insatiable greed of the super-rich and the blind extremism of their wooden-headed political allies.”) 

Conservative commentators have pointed out that Michigan is merely the most recent link in a chain of events, from the response to Wisconsin Governor Scott Walker’s decision to end collective bargaining rights for public sector unions (where Walker was often compared to Hitler, Mubarak, and Mussolini) to the Occupy Wall Street protests (which were characterized by sexual assault, arson, and vandalism, among other things).

My point isn’t that what’s happening today is anything like the scale of what Lincoln was referring to (which included murders committed by pro-slavery mobs). But the confrontations and rage, the acts of intimidation and violence we’ve seen in places from Lansing to Zuccotti Park and several other cities are troubling enough.

We all know passions can be inflamed in political disputes. What’s crucial is to respect the rights of others even when we disagree with them. Those who don’t–those who substitute wild and furious passion for cold, calculating, unimpassioned reason–are engaged in something destructive.

We are nowhere close to a pre-civil war situation. We’re even a long distance removed from the violent protests of the late 1960s and early 1970s. But our divisions are deep enough. And when differences in policies lead to screaming matches, shoving matches, provocations and fist fights, it’s not a sign of civic health. (Liberals might be somewhat more attuned to this point if the actions we’re seeing at union rallies had happened at Tea Party gatherings.)

A “mobocratic spirit” is at odds with America’s political religion. And it would be nice, and perhaps even helpful, if the president reminded his supporters and allies of that from time to time.