How is youth defined in "Th picture of Dorian Gray"

Lord Henry claims to value beauty and youth above all else. It is this belief, when imparted to Dorian, that drives the protagonist to make the wish that ultimately damns him. When Dorian realizes that he will keep his youthful appearance regardless of whatever immoral actions he indulges in, he considers himself free of the moral constraints faced by ordinary men. He values his physical appearance more than the state of his soul, which is openly displayed by the ever-increasing degradation of the portrait. This superficial faith in the ultimate value of youth and beauty is therefore the driving mechanism behind the protagonist's damnation. In this way, The Picture of Dorian Gray may be read as a moralistic tale warning against the dangers of valuing one's appearance too highly, and of neglecting one's conscience.

It is important to bear in mind that the beauty that Dorian incessantly pursues is a beauty defined by a purely artistic sensibility, as opposed to a humanitarian one. When faced with the news of his fiance's suicide, Dorian views the event as satisfyingly melodramatic. His obsession with aesthetic beauty prevents Dorian from attending to the pangs of his own conscience.

GradeSaver source-link