Linton’s character is Bronte making a point about how unsustainable a revenge-driven lifestyle can be — namely, Heathcliff’s revenge driven lifestyle. Linton’s weakness, neediness, and eventual death shows Heathcliff’s inability to create something healthy and long-lasting. Heathcliff’s constant desire for revenge, and his need to control others to exact that revenge makes his person incapable of creating a full life, and nurturing that life. Although he is physically capable of reproduction, his deep-seated emotional issues and inability to connect with most people in an honest, human ways make him less alive — and his withering son is an embodiment of that fact. Catherine’s healthy and strong character alongside Linton’s much weaker character, only further highlights this idea.
Heathcliff’s inability to connect is made apparent through Lockwood’s observations in the first few chapters. “He’ll love and hate equally undercover, and esteem it a species of impertinence to be loved or hated again (3).” Lockwood continually describes Heathcliff as trapped within himself. He cannot connect with other people or express himself; rather he “keeps his hand out of the way when he meets a would-be acquaintance (3).” Heathcliff is introduced as a mysterious, bruised shell of a person. He is alive, but barely living, and his life decisions have left him in this empty and sad state. One the book dives into his life story, it becomes apparent that at a certain point in his life, his interactions with other characters, including those with his own son, are simply means to an end. By introducing Heathcliff as a walled off, cold person, and then explaining the degradation of character that occurred in his life, Bronte illustrates how his lifestyle led to his empty state.
Linton embodies a more visible version of the detrimental effects of Heathcliff’s lifestyle. He is described as having a “sickly peevishness to his aspect,” and as being not as “strong” or as “merry” as Catherine (177). As he gets older he remains weak and unpleasant to be around. Then, he dies. Catherine, on the other hand, lives a much longer life. Just as Linton and Catherine stand in comparison to one another, Heathcliff and Edgar do as well. Although Edgar is far from perfect, he does exhibit moments of genuine care for his daughter, and is concerned with her happiness. As a result of this care, Catherine is depicted as strong and healthy, and lives a much longer life than Linton. Heathcliff, on the other hand, is not at all concerned with his child’s happiness or health, and simply uses him as a tool for inheritance.
It’s important to note Heathcliff’s story is multi-dimensional, and a number of tragic events occurred in his life that played into his decision to live a vengeful life. Bronte makes this fact clear. But also by introducing Heathcliff the way she does, and by making Linton a sick child, next to a lively child like Catherine, she is touching on the unhealthiness and the danger of Heathcliff’s way of life.