Quote 22
Often, on returning home from one of those mysterious and prolonged absences that gave rise to such strange conjecture among those who were his friends, or thought that they were so, he himself would creep upstairs to the locked room, open the door with the key that never left him now, and stand, with a mirror, in front of the portrait that Basil Hallward had painted of him, looking now at the evil and aging face on the canvas, and now at the fair young face that laughed back at him from the polished glass. The very sharpness of the contrast used to quicken his sense of pleasure. He grew more and more enamoured of his own beauty, more and more interested in the corruption of his own soul. He would examine with minute care, and sometimes with a monstrous and terrible delight, the hideous lines that seared the wrinkling forehead or crawled around the heavy sensual mouth, wondering sometimes which were the more horrible, the signs of sin or the signs of age. He would place his white hands beside the coarse bloated hands of the picture, and smile. He mocked the misshapen body and the failing limbs. (11.4)
The visible embodiment of Dorian's mortality now delights him – in some odd way, he's kind of come to terms with the grotesque decay of his painted self. The contrast with his physical body is a source of endless pleasure to him, and in comparison to the disgusting man in the painting, his youthful beauty seems all the more vibrant.
Quote 23
He used to wonder at the shallow psychology of those who conceive the ego in man as a thing simple, permanent, reliable, and of one essence. To him, man was a being with myriad lives and myriad sensations, a complex multiform creature that bore within itself strange legacies of thought and passion, and whose very flesh was tainted with the monstrous maladies of the dead. He loved to stroll through the gaunt cold picture-gallery of his country house and look at the various portraits of those whose blood flowed in his veins. (11.32)
Dorian seems to view himself as a kind of accumulation of the identities of his long-dead ancestors – his rather morbid view of identity seems to be tied to his strong identification with both his own portrait and those of his family members. He feels a distinct connection to all of these ancestors, and feels like part of them lives on through him.
Quote 24
THE next day he did not leave the house, and, indeed, spent most of the time in his own room, sick with a wild terror of dying, and yet indifferent to life itself. The consciousness of being hunted, snared, tracked down, had begun to dominate him. If the tapestry did but tremble in the wind, he shook. The dead leaves that were blown against the leaded panes seemed to him like his own wasted resolutions and wild regrets. When he closed his eyes, he saw again the sailor's face peering through the mist-stained glass, and horror seemed once more to lay its hand upon his heart. (18.1)
Finally, Dorian begins to feel his mortality directly – the threat of death at the hand of James Vane sends him into a tizzy. While death seemed impossibly distant when it was contained within the portrait, it now appears horrifying when seen up close.