In the opening passage of The Brothers, Terence indicates the complex structure of the family dynamics at hand. The eponymous brothers, Micio and Demea, are two very different men, yet they are each raising one of Demea’s sons. Their dissonant child-rearing tactics have led the two boys—Aeschinus and Ctesipho—to become vastly different men. Even still, their fathers love them dearly, and this love often leads to conflict, as it does in the opening lines of the play, as Micio mournfully reveals his anxiety over his son’s selfish independence:

How anxious that my son is not return’d; lest he take cold, or fall, or break a limb—Gods, that a man should suffer any one to wind himself so close about his heart, as to grow dearer to him than himself! And yet he is not my son, but my brother’s, whose bent of mind is wholly different.

As he worries after his son, who has not yet returned home, Micio turns to the question of his parenting and wonders if he has somehow done wrong. He explains that he has chosen to be generous and forgiving, for he feels that a young boy is more likely to listen to soft encouragement rather than abide by harsh punishment. Demea, however, does not approve of this style and feels that his brother is harming his eldest son with this lax permissiveness. 

I’m generous, I turn a blind eye, I don’t find it necessary to exert my authority all the time. In short I’ve accustomed my son not to hide from me those youthful escapades which others get up to behind their fathers’ backs. A boy who sets out to lie and deceive his father and is bold enough to do that will be all the more bold with others. I believe that it is better to discipline children by gaining their respect and showing generosity than through fear. My brother doesn’t agree with me on this; he just doesn’t approve.

Although Micio worries that his son does not respect his authority, Aeschinus appreciates his father’s parenting. He explains that, even though his father is a soft-hearted master, he still feels the need to respect his wishes: 

What about this? Is this what it means to be a father or a son? If he were a brother or a friend, how could he be more obliging? Isn’t he a man to be loved and cherished? I should say so! He’s been so considerate that I’m terribly afraid of doing something unwittingly he doesn’t like. I won’t do any such thing wittingly. But I’d better go in, or I’ll be holding up my own wedding.

After learning of Aeschinus’s actions, which have unduly resulted in the assault and impregnation of the neighbor’s daughter, a chaste virgin who neither wished for nor inspired Aeschinus’s interests, Demea offers his account of ideal fatherhood. He rages at the man his son has become and berates Micio for his parenting style, which he believes has led to these immoral happenings: 

Jupiter! What a life! What a way to behave! What madness! There’s a wife coming without a dowry, there’s a music girl inside, the house is wallowing in extravagance, the young man’s ruined by luxury, the old man’s off his head. Salvation herself couldn’t possibly save this house even if she wanted to

Demea’s closing monologue highlights the central theme of the play and speaks to the contrasting lives each brother and their respective son leads: 

... in reality nothing is better for a man than to be generous and easygoing. Anyone can easily see the truth of...