Engaging Faith: Practical lesson ideas and activities for Catholic Educators

September 4, 2012

Message of the Eighth Commandment: Tell the Truth

The Eighth Commandment is an important one for your students to consider at the start of a school year. It involves telling the truth. Use a short lesson on the Eighth Commandment—"You shall not bear false witness against your neighbor"—to explain why truth-telling and obedience to this Commandment involves keeping an honest relationship between friends. It prohibits calumny, that is speaking falsely and negatively about others. It also condemns belittling or ridiculing others. Lying itself undermines a person's relationship with others. Lies offend God who wants us to live honestly with others.

Share the following case study on truth telling. It involves the difficult choice a person must make between keeping a confidence of a friend and respecting the privacy of a conversation with the possible danger the friend may face if the confidence is not revealed. This case study and others around the Ten Commandments are included in the book The Ten Commandments: Case Studies in Catholic Morality.

Case Study: Keeping a Friend’s Secret

Sharon and Katie have been close friends since grade school. They are now high school sophomores. Katie began gaining weight in middle school, and she ignored her eating habits for a few years. Some classmates made remarks about Katie’s weight, but most said nothing about it, at least not so that she could hear them. Sharon never belittled Katie or made her weight an issue and, because of her understanding and loyalty,

Katie considers Sharon her best friend.

At the beginning of sophomore year, Katie began to be concerned about her weight and went on a diet. She was very strict with herself, and she managed to get to her goal weight in three months. True to form, Sharon did all the things a friend should do when Katie was dieting. She encouraged her, and she never once suggested that Katie go off the diet and enjoy a high-calorie treat. Sharon felt proud of Katie and happy for her when she lost the extra pounds.

Recently, Sharon has become concerned about Katie because Katie’s disposition has changed and because she has been eating junk food items and then vomiting to get rid of them. Sharon asks Katie why she spends so much time in the bathroom and asks, “You’re throwing up what you eat. Right?” Katie starts to cry and admits that she has developed a problem with eating and purging (bulimia), and she tells Sharon that this is to be a secret just between the two of them. Katie tells Sharon that she is her friend because Sharon has always been loyal and has never done anything that would hurt Katie.

Sharon is confused. She wants to respect Katie’s privacy, but she has heard that bulimia is a serious disorder, and she thinks that Katie may need professional help to stop her self-destructive behavior.


  1. Katie and Sharon are friends and, generally speaking, friends should keep secrets. What are some exceptions to this rule?
  2. What should Sharon do in this situation? Should she keep her knowledge about Katie’s problem to herself, or should she share this information?
  3. If Sharon should tell someone, who should that someone be? Why?
  4. Speculate on the reasons Katie is eating and purging, and consider constructive advice that you might give her.

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