The picture of Dorian Gray

Discuss the influence of Basil Hallward, Harry Wotton, and Sibyl Vane have on Dorian Gray. Why, after acknowledging the poisonous nature of Wotton’s influence, does Gray all it to continue? In Chapters 7 & 8, Dorian makes a decision, then reneges and chooses the opposite. What influences are at work here? What does this tell us about Gray’s character and who is ultimately responsible for his moral degeneration? When does the influence cease to be
external and become internal?