Honorary degrees are often bestowed to non-academic leaders in the arts, business, and politics. Harvard’s roster in recent years has included Kofi Annan, Bill GatesMeryl Streep, and David Souter. But Oprah’s particular brand of celebrity is not a good fit for the values of a university whose motto, Veritas, means truth. Oprah’s passionate advocacy extends, unfortunately, to a hearty embrace of phony science. Critics have taken Oprah to task for years for her energetic shilling on behalf of peddlers of quack medicine. Most notoriously, Oprah’s validation of Jenny McCarthy’s discredited claim that vaccines cause autism has no doubt contributed to much harm through the foolish avoidance of vaccines.

Famous people are entitled to a few foibles, like the rest of us, and the choice of commencement speakers often reflects a balance of institutional priorities, allegiances, and aspirations. Judging from our conversations with many students, Oprah was a widely popular choice.

But this vote of confidence in Oprah sends a troubling message at precisely the time when American universities need to do more, not less, to advance the cause of reason. As former Dean of Harvard College, Harry Lewis, pointedly noted in a blog post about his objections, “It seems very odd for Harvard to honor such a high profile popularizer of the irrational. I can’t square this in my mind, at a time when political and religious nonsense so imperil the rule of reason in this allegedly enlightened democracy and around the world.”