It's that time of year again — time to fight over commencement speakers. It happens every May. Some Catholic college will feature a speaker who has taken public positions at odds with the church's teaching.

This year the University of San Francisco's law school invited Xavier Becerra, California's pro-abortion attorney general. (USF didn't give him an honorary degree, an interesting wrinkle.)

Universities shouldn't cause scandal by honoring or giving public signals of agreement with people who promote grave injustice. As the American bishops have put it, Catholic institutions "should not honor those who act in defiance of our fundamental moral principles. They should not be given awards, honors or platforms which would suggest support for their actions."

It's hard to argue with that. But I wish we would view our annual commencement exercises as something more than an opportunity to avoid causing scandal. (I could accomplish that much by giving the commencement address myself, though I suspect that after a few years, parents and graduates would skip the exercise.)

Ideally, our graduation rituals should have a positive purpose. I don't just mean getting good publicity by attaching ourselves to somebody famous and making the evening news on a slow day.

At Catholic University, we try to invite people who offer our graduates examples of what they should aspire to in life, now that they have completed their studies. "You are finished now," we say. "Go and do as these people have done."

This was our practice long before I became president. The speakers and honorary degree recipients we have held up for our students' emulation over the years have included at least two saints: Mother Teresa of Kolkata (1971) and St. Katharine Drexel (1939). Venerable Archbishop Fulton J. Sheen, a member of our faculty for 23 years, spoke in 1975.

In recent years, we have given honorary degrees to the founders and leaders of influential lay movements in the church: Communion and Liberation, Focolare, the Neocatechumenal Way, Community of Sant'Egidio, Instituto Fe y Vida.

We have honored great thinkers (Etienne Gilson, Jean Piaget, Jaroslav Pelikan, John Hope Franklin, Dana Gioia); athletes (Roger Staubach, Philip Rivers); judges (John T. Noonan Jr., Antonin Scalia, Samuel Alito); comedians (Bob Newhart, Jim and Jeanne Gaffigan); and musicians (Mstislav Rostropovich, Manfred Honeck). 

This year we invited Peggy Noonan of The Wall Street Journal— a public thinker, author, historian and journalist. Last month, she won a Pulitzer Prize in commentary for her far-sighted columns on the rise of President Donald Trump, an event that caught most Americans by surprise.

The commencement addresses we have heard from some of these people have been inspiring. But having attended far more graduations than the average person, I think I have learned two things that may help in the selection process. 

The first is that nobody remembers what the speaker says. This is not because the talks are bad. Some are really good. It's because the graduates' minds, and their parents', are fixed on the life-changing events of the weekend, and it's hard to pay attention.

The second is that people do remember who the speaker was. Commencement speakers do communicate an important parting lesson. But the lesson is embodied in the life of the honoree. This should not be so surprising. Isn't this how we always learn the practice of virtue? 

Virtue is a habit, not a bit of information. We acquire it by copying good examples. St. Bonaventure, in his little treatise "Bringing Forth Christ," advises, "Seek the company of good people. If you share their company, you will also share their virtue." If we keep that thought in mind, we are less likely to cause a stir by inviting someone unworthy of the honor. 

Garvey is president of Catholic University in Washington.