The title character of Tuesdays With Morrie has spent most of his life as a professor of sociology at Brandeis University, a position he has fallen into only "by default." He is an excellent teacher, and retires only after he begins to lose control of his body to ALS, Amyotrophic Lateral Sclerosis, also known as Lou Gherig's disease. The disease ravages his body, but, ironically, leaves his mind as lucid as ever. He realizes that his time is running out, and that he must share his wisdom on "The Meaning of Life" with the world before it is too late to do so. Mitch serves as a vehicle through which he can convey this wisdom, to Mitch personally, and, more indirectly, to a larger audience which he reaches after his death by means of the book itself. He and Mitch plan for the book during his dying days, deeming it their "final thesis together." He is also able to reach a vast audience through his interviews with Ted Koppel, which are broadcast nation-wide on ABC-TV's "Nightline."

Morrie has an unmistakable knack for reaching through to the human essence of every individual he befriends. He is even able to deconstruct Koppel, who is a thick-skinned national celebrity. He does so by asking Koppel what he feels is "close to his heart." Love is his main method of communication. Just as he reaches Koppel through his thick celebrity skin, he reaches Mitch through his dense veneer of professionalism and greed. He sees that Mitch has surrendered his sense of self to the beliefs of popular culture, and urges him to reclaim the kind, caring young man he once was at Brandeis. In telling Mitch stories of his life experiences and personal beliefs, he teaches him to reject the corrupt mores endorsed by popular culture in favor of his personal, ethical system of values. He does not immerse himself in the media as most of America does, but instead invests himself in people and their potential to love.

Morrie also chooses to react against popular cultural norms in his acceptance of his own debilitating disease and imminent death. He has lived and loved to his fullest extent, and is intent on continuing to do so as he dies. Having always lived as a fiercely independent man, it is difficult for him to rely on others for all of his basic needs, though he refuses to be embarrassed by his physical shortcomings, and tries in earnest to enjoy "being a baby again." In his childhood, he has been deprived of love and attention, and now that he is once again reliant on others as he was in his infancy, he thrives on the love and physical affection provided by his friends and family.