What makes a traditional college education worth the price? That is the question those of us in higher education are increasingly called upon to answer, as tuition at brick and mortar institutions continues to rise, and as ever more inexpensive on-line college courses become available.

The events of Colby’s commencement last weekend reminded me that the answer has to be the people — the faculty and coaches, friends and classmates who define the world of a residential college.

When our graduating seniors talk about their education, they have plenty to say about what they know. They can tell you about the books they’ve read, and they can summarize the paper they wrote for a senior seminar or explain the experiment they designed or conducted. They can talk about the skills they’ve acquired, the coursework they’ve completed, the research they’ve done.

But that’s not what our graduates really want to talk about. They want to talk about the people who have touched their lives.

They want to tell you about the coach who helped a bunch of strangers come together as a team. They want to talk about the other students in the study group they worked with to master the material in a particularly challenging course. They want to tell you about the professor who inspired them to love some academic discipline they had not even heard of in high school.

There is good evidence that on-line courses do a good job of imparting certain kinds of information, and that result isn’t very surprising. Some students have always been able to teach themselves even very challenging material by simply reading the textbook. It should come as no surprise that these students and a few more can teach themselves college-level material by watching video lectures, taking automated tests, and reading textbook assignments.

Great teachers do much more than impart skills and knowledge, however. The greatest of all teachers, Plato, in the greatest of his dialogues, The Republic, long ago repudiated the idea that the task of education is to “put into the soul knowledge that isn’t in it, as though (one) were putting sight into blind eyes.”

As he saw it, the task was instead to turn around the student’s mind or soul, redirecting attention away from the ephemeral and trivial and towards what is enduring and truly worth knowing.

Very few students go to college knowing what they really want to study or what career they will pursue. Most come looking for direction and inspiration, as well as to acquire useful knowledge and marketable skills.

Direction and inspiration, however, love and happiness, are things we very much desire but that cannot be imposed or grasped directly.

Great teachers can and do inspire, but not by trying to “be inspirational,” whatever that would mean, but rather by letting students and colleagues see in their teaching and scholarship how much they love what they do, how their studies shape and enrich who they are, providing meaning and direction in their lives.

One of the traditional tasks of college is to broaden students’ horizons, to awaken them to disciplines and modes of thinking that they had never encountered before. But no one can really know what it feels like to be a political scientist a biologist before learning the habits of thought and mastering the body of knowledge that constitutes those disciplines. What successfully inspirational teachers do is to enable students to see in advance, through their example, what those ways of knowing look like in the lives of real people.

Before you know anything much about French poetry, for example, you have no way of really appreciating why anyone would care about it.

But when you meet a teacher, for whom the works come alive and whose life and career testify to the transformative power of those words, you can get an intimation of what it will mean to you to have learned it. And so you will be inspired to turn yourself around to the task of immersing yourself deeply in a subject that, not long before, you would have ridiculed.

Skeptics will ask whether there can be any lasting benefit to college, when most of the detailed knowledge our students learn is outdated or forgotten (or both) before their fifth reunion. They will be able to look back on the obscure or old books they read and the old experiments they conducted, as they do on the inspiring people who taught them, as old friends.

Joseph R. Reisert is associate professor of American constitutional law and chairman of the department of government at Colby College in Waterville.