Friendship is an important theme in The Picture of Dorian Gray, The Strange Case of Dr. Jekyll and Mr. Hyde, and Silas Marner primarily because the protagonists are basically loners who lack real friends. A closely related common trait that the protagonists share is that they are all keeping secrets. Of the three men, only Silas becomes capable of friendship; the other two die.
Dorian Gray has a large social circle, but the egotistical man grows increasingly distant from all these acquaintances as they age while he does not. His secret is the sinister pact he has made to have his portrait age instead of him. His inability to connect genuinely with others is shown by his rejection of Sybil. Dorian’s embrace of hedonism turns fatal when he kills Basil, the portraitist, and then himself by destroying the portrait.
Dr. Jekyll is initially on good terms with his lawyer, Utterson, and an acquaintance, Lanyon, but seems to have no true friends. He becomes increasingly reclusive as the Hyde personality takes over and, finally, takes his own life.
Silas Marner is portrayed as having good reason to give up on friendship. In his former community, Lantern Yard, he was framed by William Dane, whom he considered a close friend. After moving to Raveloe, he is a recluse until finding Eppie. Largely through the little girl’s friendship with Aaron, Silas begins to make friends, beginning with the boy’s mother, Dolly. Being welcomed and trusted in the community helps him recover his faith in friendship.