Three characters hum about the center of The Portrait of Dorian Gray, serving as foils for one another and for Dorian. First is Basil Hallward, who in painting Dorian Gray unwittingly gives the man the enabling tool of his downfall. Second is Lord Henry, whose words corrupt Dorian and lead him to make his unholy pact with his portrait in the hopes of preserving his youth. Third is Dorian Gray himself, who—influenced by the pressures of these previous two figures—stumbles his way into the hedonistic life and, from there, to his death. Both Basil and Henry act as foils for each other and for Dorian, emphasizing through their juxtaposition their deep-set ideologies and visions for how Dorian should live his life.
From Henry’s very introduction, he tries to influence Dorian with his thoughts on the hedonistic lifestyle:
The only way to get rid of a temptation is to yield to it. Resist it, and your soul grows sick with longing for the things it has forbidden to itself, with desire for what its monstrous laws have made monstrous and unlawful.
As soon as he begins sharing his philosophy, however, Basil attempts to intervene. As Dorian sits for his portrait, Basil admonishes Henry and warns Dorian not to listen to his words. Dorian is not to pay "any attention” to Lord Henry, Basil advises. “He has a very bad influence over all his friends, with the single exception of myself.”
As the plot unfolds, Basil and Henry come to represent decidedly different paths for Dorian to follow. Basil aligns himself with Christian morality, and an appeal to good faith, while Henry identifies himself with a “Hellenistic” ideal—the ancient indulgences of the Greeks themselves. Using this worldview, Henry is able to convince Dorian to try on hedonism for size:
Live! Live the wonderful life that is in you! Let nothing be lost upon you. Be always searching for new sensations. Be afraid of nothing. . . . A new Hedonism—that is what our century wants. You might be its visible symbol. With your personality there is nothing you could not do.
Despite Basil’s warning, Dorian falls prey to this speech and dives headlong into his new self-serving mindset. As a foil for Dorian, Henry stokes his obsession with his own youth and his fear of aging, emphasizing the selfish qualities and capacity for cruelty Basil himself observes in Dorian early on.
Through the use of the characters of Basil and Henry as foils to Dorian Gray and to each other, Wilde builds enormous tension in the narrative and keeps the reader constantly following the persuasive—and increasingly insistent—appeals of both characters.