But the potential benefits of the law are slight, and dubious at best. It turns out, for example, there were armed students at Umpqua Community College in Oregon on the day of its shooting last fall. Their presence did not deter the attack, nor did they halt it; the students wisely decided not to jump into the fray for fear it would compound the mayhem.

By contrast, campus carry’s potential for harm is quite real. Its principal threat is less than obvious, however; its impact may not be physically manifest at all. I’m counting its cost in terms of what is lost in the classroom—and it is a loss that may be deeply damaging to the country’s democracy.

This can be gleaned from the faculty concerns at the University of Houston. In short, they argued that guns in the classroom pose an intolerable threat to free speech. It’s unclear whether campus carry does and will in fact undermine the freedom of expression, but if there’s one place in society where the citizenry must not tolerate such threats, it’s the college classroom. The college classroom is meant to be a special space where all manner of ideas are aired, considered, and debated, and differences negotiated—through speech and argument—with no fear of violent recrimination, no fear of inciting angry students to draw their guns.

In my philosophy and politics classes, for example, I—like peers in my field—routinely broach contentious issues: topics such as structural racism, abortion, and gun rights (the most contentious of them all). Few young adults have put significant thought into these kinds of issues; they must experiment with them to understand them properly and deeply, and to develop mature and critical views. It’s important to ensure that students feel free to explore their thoughts and express them—frankly—so they can experiment and develop. They must feel free to push their intellectual limits, and entertain lines of argument that are controversial, probably offensive to some.

It is a goal, an often elusive ideal, that the college classroom be that space where the circulation and contest of ideas are freewheeling and dynamic, as ideas are subjected to the close inspection of logic, and measured in the light of history and personal experience. This can—and many will say should—be a raucous affair on occasion.

It seems that campus carry stands opposed to these pedagogical goals. Will guns encourage speech and invite people to discussion and debate in the classroom? The reality could be quite to the contrary: Guns could have a chastening effect. If students suspect that neighbors in the classroom may be armed, this may make them less inclined to engage them in frank and open discussion, on potentially uncomfortable or challenging topics. Guns speak; they send a message, which, gun owners and gun rights advocates readily admit, is something like this: Don’t mess with me—be careful—I am armed; I know how to use my weapon, and am prepared to do so if need be. Thanks to Stand Your Ground, they may draw their weapons on merely perceived threats.