"The Picture of Dorian Gray" is a philosophical novel, written by writer and playwright Oscar Wilde. It portrays the superficial nature of society, and the supremacy of youth and beauty. Furthermore, it discusses the purpose of art and aestheticism. One of the theme of the novels, frequently discussed by the characters of the book itself, is influence and its consequences. As Lord Henry says early on in the novel, "All influence is immoral." (Wilde 20). The novel depicts influence as something that is immoral and damaging, for it hinders an individual from truly prospering to their potential and becoming who they were supposed to.
The portrait of Dorian, along with the yellow book, is a representation of the profound and harmful influence art may have over an individual. They have a profound effect on Dorian, influencing him to show predominantly immoral behavior over the course of nearly two decades. The yellow book is a gift to Dorian from Lord Henry. The author describes the book as a French novel that charts the outrageous experiences and adventures of its pleasure-seeking protagonist. Dorian is so fascinated and enthralled by this book, that he bases his actions and judgments, perhaps even his whole life, upon it. It becomes his Bible, and dictates his life. ("For years, Dorian Gray could not free himself from the influence of this book." (127)) Dorian does, however, notice the influence of the book - "You poisoned me with a book once. I should not forgive that. Harry, promise me that you will never lend that book to anyone. It does harm." (215). The portrait, referred on an occasion by the author as "the most magical of mirrors", on the other hand, acts as his conscience and shows him his crimes. On the portrait, he sees how cruel he had been towards Sibyl Vane, and the blood of Basil Hallward that he spilled. It illustrates to Dorian the physical burdens of aging and sinful life which he avoided.