Michael A. McRobbie, president of Indiana University, writes:  On Sunday, as part of her moving and well-received speech at the Golden Globe Awards telecast, Oprah Winfrey expressed gratitude to those individuals with an “insatiable dedication to uncovering the absolute truth that keeps us from turning a blind eye to corruption and to injustice.”  We might be wise to emblazon Winfrey’s words on the diplomas of all of today’s college graduates, who will enter what is increasingly being called the “post-truth era” — a time in which there is a growing and disturbingly widespread disregard of truth, and truth is increasingly ignored in favor of prejudice.