Although the primary attribute Wilde ascribes to Dorian Gray at first is extreme beauty, his portrait painter Basil Hallward also notes a darker side to the character in the opening chapter, foreshadowing Gray's fall from grace:
As a rule, he is charming to me, and we sit in the studio and talk of a thousand things. Now and then, however, he is horribly thoughtless, and he seems to take a real delight in giving me pain. Then I feel, Harry, that I have given away my whole soul to some one who treats it as if it were a flower to put in his coat, a bit of decoration to charm his vanity, an ornament for a summer's day.
Although this is an offhand comment to Lord Henry, Basil has nonetheless identified in Dorian a capacity for cruelty that will eventually enable him to live an increasingly selfish life and, ultimately, to kill Basil—a capacity that starts out with a mild sadistic streak and a tendency to use others and unravels into murder. It is a prime example of how Wilde uses offhand comments to build suspense in the reader and foreshadow the novel’s descent from its initial extravagant aestheticism into its ultimate Gothic horror.
In Chapter 1, when Lord Henry first introduces Dorian, and the reader, to his take on hedonism, he references the ancient Hellenic, or Greek, world:
I believe that the world would gain such a fresh impulse of joy that we would forget all the maladies of mediaevalism, and return to the Hellenic ideal—to something finer, richer than the Hellenic ideal, it may be.
Given that he associates the excesses of his personal philosophy with the supposed excesses of the classical world, it makes sense that many of the allusions he makes are to figures of Greek and Roman myth. When discussing Dorian’s beauty with Basil in Chapter 2, he repeatedly draws comparisons between Dorian and famously beautiful men of myth:
Upon my word, Basil, I didn’t know you were so vain; and I really can’t see any resemblance between you, with your rugged strong face and your coal-black hair, and this young Adonis, who looks as if he was made out of ivory and rose-leaves. Why, my dear Basil, he is a Narcissus, and you—well, of course you have an intellectual expression and all that.
While both Adonis and Narcissus are perhaps most famous for their beauty, there is an element of irony to both these comparisons because both of these figures meet disastrous ends. According to his myth, Adonis, who is so good-looking that the goddess Aphrodite herself falls in love with him, dies in a horrible hunting accident—an accident not dissimilar from the one that ultimately leads to James Vane’s death later in The Portrait of Dorian Gray. Narcissus, on the other hand, dies as a direct result of his beauty: falling in love with his own reflection, he famously wastes away in front of a pool of water. Although Henry’s invocation of both these figures is ostensibly a compliment to Dorian’s beauty, their mythic demises foreshadow the hedonistic chaos that will eventually lead to the death of James Vane, Basil Hallward, and Dorian himself—a chaos that begins because Dorian, like Narcissus, is unwilling to relinquish his own beauty.
In the beginning of The Portrait of Dorian Gray, Wilde uses foreshadowing to hint at Dorian's eventual obsession with aging. It is Lord Henry who inspires Dorian to fear aging above almost all else, and by emphasizing Henry’s own preoccupation with Dorian’s aging at the beginning of the novel, Wilde foreshadows Dorian’s eventual willingness to sacrifice all else in service of his beauty:
“Let us go and sit in the shade,” said Lord Henry. "[...] You really must not allow yourself to become sunburnt. It would be unbecoming.”
“What can it matter?” cried Dorian Gray, laughing, as he sat down on the seat at the end of the garden.
“It should matter everything to you, Mr. Gray.”
“Why?”
“Because you have the most marvellous youth, and youth is the one thing worth having.”
The threat of the sunburn is more than just a concern for Dorian's long-term wellbeing—his beauty is closely associated with his pale white skin throughout the novel, and a sunburn would certainly harm his appearance.
Henry’s final remark in this passage, that “youth is the one thing worth having,” will become an unconscious refrain for Dorian’s character as he navigates an increasingly shameful and destructive life. Through foreshadowing, Wilde establishes early on the hold that Henry will have over Dorian for the remainder of the novel and leaves breadcrumbs with which the reader may trace the exact moments at which Dorian begins to fall prey to Henry’s hedonistic philosophy.
When Lord Henry first introduces his hedonistic philosophy to Dorian, while he sits for his portrait, Basil warns Dorian not to listen to Henry’s words and Dorian himself questions whether such self-serving ideation is a bad influence upon him. In a moment of irony, Henry responds,
There is no such thing as a good influence, Mr. Gray. All influence is immoral—immoral from the scientific point of view.
The irony here is that Henry's sole intention in speaking to Dorian is to influence him, and thus his words reveal either that he has no knowledge of his own immorality or that he has abandoned morality entirely. As it turns out, the man wishing to influence Dorian is all too aware of the dangers of such influence:
[…] to influence a person is to give him one’s own soul. He does not think his natural thoughts, or burn with his natural passions. His virtues are not real to him. His sins, if there are such things as sins, are borrowed. He becomes an echo of some one else’s music, an actor of a part that has not been written for him.
In this moment of reflection, Henry is darkly foreshadowing Dorian’s fall from grace that is still to come. Over the remainder of the novel, as Dorian succumbs to Henry’s self-serving ideology, he will become “an echo” of Henry’s philosophy—which, not coincidentally, Wilde frequently describes in terms of its “sweet music” and capacity to persuade like the sound of a beautiful instrument. It is darkly ironic that Henry should know everything about the dangers of influence and yet choose to barge ahead with his damaging speeches to Dorian. These passages would have been especially remarkable to a nineteenth-century reader of The Portrait of Dorian Gray, because outspoken critics accused the book itself of having an undue influence on its readers and driving them to immorality.
In Chapter 1, when Lord Henry first introduces Dorian, and the reader, to his take on hedonism, he references the ancient Hellenic, or Greek, world:
I believe that the world would gain such a fresh impulse of joy that we would forget all the maladies of mediaevalism, and return to the Hellenic ideal—to something finer, richer than the Hellenic ideal, it may be.
Given that he associates the excesses of his personal philosophy with the supposed excesses of the classical world, it makes sense that many of the allusions he makes are to figures of Greek and Roman myth. When discussing Dorian’s beauty with Basil in Chapter 2, he repeatedly draws comparisons between Dorian and famously beautiful men of myth:
Upon my word, Basil, I didn’t know you were so vain; and I really can’t see any resemblance between you, with your rugged strong face and your coal-black hair, and this young Adonis, who looks as if he was made out of ivory and rose-leaves. Why, my dear Basil, he is a Narcissus, and you—well, of course you have an intellectual expression and all that.
While both Adonis and Narcissus are perhaps most famous for their beauty, there is an element of irony to both these comparisons because both of these figures meet disastrous ends. According to his myth, Adonis, who is so good-looking that the goddess Aphrodite herself falls in love with him, dies in a horrible hunting accident—an accident not dissimilar from the one that ultimately leads to James Vane’s death later in The Portrait of Dorian Gray. Narcissus, on the other hand, dies as a direct result of his beauty: falling in love with his own reflection, he famously wastes away in front of a pool of water. Although Henry’s invocation of both these figures is ostensibly a compliment to Dorian’s beauty, their mythic demises foreshadow the hedonistic chaos that will eventually lead to the death of James Vane, Basil Hallward, and Dorian himself—a chaos that begins because Dorian, like Narcissus, is unwilling to relinquish his own beauty.
Wilde makes ample allusions to Shakespeare and his plays in Dorian Gray. This is unsurprising, given the emphasis the book places on the enjoyment of the arts and the titular character's particular enthusiasm for theater. Perhaps the most significant allusion is to Shakespeare's most famous play, Romeo and Juliet, which occurs during Dorian's courtship of the actress Sybil Vane:
Yet she was curiously listless. She showed no sign of joy when her eyes rested on Romeo. The few words she had to speak [...] were spoken in a thoroughly artificial manner. The voice was exquisite, but from the point of view of tone it was absolutely false. It was wrong in color. It took away all the life from the verse. It made the passion unreal.
Given that Dorian is wholly consumed by the preservation of beauty, Sybil’s botched performance as Juliet—due to Gray’s presence, no less—is especially horrifying to him. This passage represents the first pronounced negative effect the reader sees of Dorian’s exploration into London's underbelly, and also functions as a brilliant bit of foreshadowing: the play famously ends in the title characters' suicides, and Sybil Vane will take her own life after Dorian loses interest in her art and abandons her.