LitCharts assigns a color and icon to each theme in The Picture of Dorian Gray, which you can use to track the themes throughout the work.
The Mortality of Beauty and Youth
Surfaces, Objects and Appearances
Art and the Imitation of Life
Influence
Women and Men
Summary
Analysis
The novel begins with a short preface, a line of reasoning that suggests that Art has no purpose and all beauty is useless. It is an argument introducing the themes of the story to follow.
The preface makes us aware of the novel to follow as a work of art, so we enter the story unsure of whether to believe in it or see it as “useless.”