In his short story, "The Weapon," Frederic Brown shows, rather than tells us what the protagonist, Dr. Graham, is like. Brown does this through Dr. Graham's interactions with other characters, through his dialogue, and through his thoughts. At no point in the story does Brown describe what Dr. Graham looks like.
Brown shows us that Dr. Graham is a loving father through his interactions with his "mentally arrested son." When Graham speaks to his son, his voice is "warm with affection." When his son moves towards the stranger, named Niemand, Dr. Graham pulls him back "gently." When his son asks if he will read to him, Dr. Graham "put[s] an arm around the boy," in a loving, reassuring manner.
Brown also shows us that Dr. Graham is anxious and caring, and he does so not simply by telling us that he is anxious and caring, but by showing to us Dr. Graham's thoughts. For example, at the beginning of the story, Brown writes that Dr. Graham thought "Mostly . . . about his mentally arrested son," and later writes that Dr. Graham admits the stranger into his home because he thinks that "A few minutes conversation . . . might divert his thoughts and clear his mind." From these quotations, we can infer that Dr. Graham cares very much for his son, and is also anxious about what might become of his son. Dr. Graham also thinks to himself, "The boy was happy; wasn't that the main thing?" This quotation emphasizes how caring Dr. Graham is—he is always thinking about, and worrying about the well-being of his son.
We also learn, through his dialogue with Niemand, that Dr. Graham is polite. He asks Niemand, "Care for a drink?" Niemand initially refuses, but when he changes his mind, Dr. Graham replies, "Certainly. Will whisky and water do?" Dr. Graham's exchanges with Niemand are always polite, even though he is momentarily irritated by his questions.