Through the protagonist, Dorian Gray, Oscar Wilde suggests that there is a cost to a life dedicated to narrow, superficial indulgence.
Dorian Gray's desires represent the dangers in superficiality. He indulges in his desire for beauty. When Dorian says that “I don't want to be at the mercy of my emotions. I want to use them, to enjoy them, and to dominate them," it reflects a superficiality that is him. Wilde uses this narrow indulgence to discuss why everything Dorian Gray does and represents is destructive. His lack of a substantive moral compass, a willingness to embrace degradation without thought, the obsession about external appearance are all aspects rooted in an embrace of the superficial. Through Dorian Gray, Wilde is able to embrace a discussion about Lord Henry's ideas which claim "to cure the soul by means of the senses, and the senses by means of the soul.” This proves ultimately shallow. The wrinkled and decrepit Dorian Gray at the novel's end proves this.
Wilde presents Dorian Gray, and all human beings, as having two choices. We can either embrace the life of superficial indulgence of the senses or we can pledge ourselves to something more meaningful. Strict adherence to any dogma brings unfortunate consequences, as demonstrated in Dorian Gray's interpretation of philosophy. When Wilde says that “All excess, as well as all renunciation, brings its own punishment," it is reminder of how the struggle between the "two selves" is a necessary part of consciousness. There can be no easy answers to this question, something that Dorian Gray himself sadly proves.