David M. Perry is an associate professor of history at Dominican University in Illinois. He writes regularly at his blog: How Did We Get Into This Mess? Follow him on Twitter. The opinions expressed in this commentary are his.

(CNN) Despite the many highly publicized campus shootings in 2015, the elected legislators of Texas have decided to put more guns on campus. They passed Senate Bill 11. The bill doesn't go into effect until next August, but education itself is already a casualty.

The University of Houston, a school of over 43,000 students, is currently trying to figure out how to implement the bill while maintaining its academic mission. It doesn't seem to be working. Over the last few weeks, Dr. Jonathan Snow, geochemistry professor and president of the faculty senate at Houston, has been sharing a slideshow at faculty forums in order to advise his colleagues how to keep themselves safe by adjusting their teaching.

"You may want to

• Be careful discussing sensitive topics.

• Drop certain topics from your curriculum

• Not "go there" if you sense anger.

• Limit student access off hours.

• Go to appointment-only office hours

• Only meet 'that student' in controlled circumstances"

Overall, the slides urge faculty to persuade students to leave their guns at home, if possible, offering rhetorical advice on how to do so without violating the law or making anyone angry. Still, the likelihood is that some students will choose to bring concealed weapons anyway, so faculty must be ready.

Every one of these bullet points conflicts with basic principles of what makes education work. As a teacher, my job is to raise difficult topics, push students to think about topics in new ways, and to assess their work, even if that process can sometimes be uncomfortable.

This is not just true in the classroom. One of the things that makes a college campus special is the way students and faculty interact generally, whether through long drop-in conversations in office hours, contact at social events or in cafeterias, or otherwise partaking in the unquantifiable, but very real, benefits of shared community.

In fact, the University of Houston uses engagement as a metric with which to measure student success. Now, professors are being advised to stick to uncontroversial topics and to limit their physical access to students.

It's important to be clear that this distressing advice is not the fault of the faculty senate. What else can they do but try to help their faculty members be as safe and law-abiding as possible? The costs of following this advice, though, are very real.

Photos: Shooting at Oregon community college Photos: Shooting at Oregon community college Community members attend a candlelight vigil at Stewart Park for those killed during a shooting at Umpqua Community College in Roseburg, Oregon, on Thursday, October 1. The massacre left nine people dead and nine wounded. The gunman also died. Hide Caption 1 of 15 Photos: Shooting at Oregon community college In response to the shooting on October 1, President Barack Obama delivers the 15th statement of his presidency addressing gun violence. "Somehow this has become routine," he said. "The reporting is routine. My response here at this podium ends up being routine, the conversation in the aftermath of it. We've become numb to this." Hide Caption 2 of 15 Photos: Shooting at Oregon community college Students and faculty are reunited with friends and family at the county fairgrounds on October 1. Hide Caption 3 of 15 Photos: Shooting at Oregon community college People wait for information at the fairgrounds on October 1. Hide Caption 4 of 15 Photos: Shooting at Oregon community college Hannah Miles, center, is reunited with her sister Hailey and father, Gary, on October 1. Hide Caption 5 of 15 Photos: Shooting at Oregon community college A student waits to walk off a school bus at the fairgrounds on October 1. Hide Caption 6 of 15 Photos: Shooting at Oregon community college Friends and family are reunited on October 1. Hide Caption 7 of 15 Photos: Shooting at Oregon community college A woman is comforted after the deadly shooting at Umpqua Community College in Roseburg, Oregon, on October 1. Douglas County Sheriff John Hanlin announced at a news conference that the shooter was dead. Hide Caption 8 of 15 Photos: Shooting at Oregon community college Authorities secure the campus after the shooting on October 1. Hide Caption 9 of 15 Photos: Shooting at Oregon community college Students, staff and faculty leave the school on October 1. Hide Caption 10 of 15 Photos: Shooting at Oregon community college A bullet casing is marked at the scene of the shooting on October 1. Hide Caption 11 of 15 Photos: Shooting at Oregon community college People gather at a roadblock near the entrance to the college on October 1. Hide Caption 12 of 15 Photos: Shooting at Oregon community college Authorities respond after reports of the shooting on October 1. Hide Caption 13 of 15 Photos: Shooting at Oregon community college Police search students outside the school on October 1. Hide Caption 14 of 15 Photos: Shooting at Oregon community college A patient is wheeled into the emergency room at Mercy Medical Center in Roseburg on October 1. Hide Caption 15 of 15

I can't really imagine how I would teach in such a situation. I teach the history of the Crusades, about gender and violence, disability and discrimination, and many other difficult subjects. I give plenty of "As," but I also give plenty of "Fs." Students find some topics upsetting.

Students find bad grades upsetting. I couldn't be a good teacher in a context where I was forced to fear armed students. Even worse, speaking as an educator, I try to foster fervent, but respectful, debate among my students. They learn better from each other than from me. Would that kind of contact among peers even be possible if a student fears their classmate might be carrying?

In the end, this is a question of free speech. There's been a lot of talk about speech rights on campus over the past few years, as pundits, politicians, and professors have argued about trigger warnings or demands for more politically correct speech. People worried about liberal students argue that if we coddle them, if we don't expose them to disturbing ideas, they won't learn anything.

I am not worried about trigger warnings. It's the literal triggers attached to firearms that represent the real threat not only to free speech on campus, but to educational mission of our great public universities and colleges. Soon, only students who can afford to go to private schools, which are allowed to opt out of this bill, will be able to do so without fear of armed classmates.

Texas is not alone. Over the last few years, eight states have officially told public universities to permit concealed firearms on campus. The Georgia House passed a campus carry bill earlier this week . Ten other states have bills pending.

By chance, the Republican candidates for president are coming to the University of Houston for their next debate on CNN on Thursday evening . They are all strong supporters of the Second Amendment, but they should pause to listen to Jonathan Snow's warnings. He recently told his Board of Regents (as recorded on video), "This is not political."

He cited famed conservative Kenneth Starr, now president of nearby Baylor, a private school. Starr is pro-gun, but has come out against campus carry. Snow said, "Academics know that the intrusion of gun culture into campus inevitably harms the academic enterprise."

Universities do need to develop appropriate partnerships with trained, armed, uniformed, law enforcement. Big schools will have their police departments. Little schools may be able to rely on local cops. Security on campus matters.

But we can't teach or learn if we are afraid of each other. We cannot arm our way out of this crisis.