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.
Mitch is a man with a good heart who has surrendered his dreams of becoming a musician to dreams of material wealth and professional success. He has grown disillusioned and values money over love. After working himself nearly to death, leaving little time for himself or his wife Janine, the union to which he belongs at the Detroit newspaper he works for goes on a long strike, and for the first time, he finds himself with neither work nor a steady paycheck. Upon learning of the strike, he grows increasingly frustrated by the career and life decisions he has made, and experiences a life-altering epiphany in which he realizes that he needs to change. He wants a chance at self-redemption, a chance to reassess his priorities so that he may recreate for himself a fulfilling life, enriched with people and activities that give him meaning and purpose.
It is only with Morrie's encouragement that Mitch is able to realize the time he has wasted in all of the years he has immersed himself in work that now seems relatively meaningless. With each week he travels to visit Morrie and listen to his lessons, his view of what he has missed and what he must change in his life becomes more lucid. As he watches Morrie die, he realizes that, like his professor, he wants to die knowing that he has lived his life to its fullest extent, certain that he has loved and forgiven himself and others as often and as sincerely as he could. He sees in Morrie the man he aspires to be, a man who values love over money, and people over tabloid gossip and superficial vanity. It is because of Morrie's influence that he is able to change his own life and outlook to become more like his professor, his mentor, who has encouraged him to be loving and kind since his college days, when he walked around campus with a veneer of toughness. Only Morrie can penetrate the toughness that has grown around Mitch's heart, which he ultimately succeeds in doing.
Mitch's younger brother, Peter lives in Spain after having moved to Europe immediately after graduating from high school. He is now suffering from pancreatic cancer, and flies to various European cities seeking treatment. However, he continually refuses to accept help from his family, namely from Mitch, as he has, for the most part, estranged himself from them after his departure from the United States. He does not want help from Mitch or any other member of his family presumably because he has too much pride to accept it. Growing up, he earned a reputation as the family bad boy, as where Mitch had been the family's clean-cut, straight-A student. Mitch's brother is a man who does not want help from a family he has deserted, and who feels that he must prove himself and his independence to them.
Much like Mitch had during his college years at Brandeis, Peter protects himself with a thick veneer of toughness. He has not asked for help from his family since his high school graduation, and has no intention of doing so as an adult. When Mitch contacts him, he is very reluctant to reestablish a relationship with his brother, and leaves a curt message that he is doing just fine and does not need anyone else's help. He also reminds Mitch that he does not want to talk about his illness. But as Mitch learns from Morrie, everyone, to some degree, needs other people to survive, thus the quote by Auden which Morrie recites numerous times during his lessons with Mitch, "Love or perish." Despite his fierce independence and refusal of help, Peter also needs the love of friends and family to survive his cancer. He realizes this after Mitch is persistent in his attempts to speak with him. Mitch does not contact his brother so that he may pity or dote on him because of his cancer, but because he wants to rekindle some aspect of the loving relationship they shared as children.