Those who go beneath the surface do so at their peril.
Those who read the symbol do so at their peril.
It is the spectator, and not life, that art really mirrors.
-From the preface to The Picture of Dorian Grey by Oscar Wilde
In Plato's Republic he gives the opinion that most art, generally speaking, is a really terrible thing. Plato's reason has to do with his idea of the forms, to which Plato were these unchanging ethereal objects of awesomeness, from everything in our world is a copy of. Art therefore - be it a painting of a bed or the story of tragic lovers - exists as a copy of something that was already a copy to begin with. What Plato was getting at, in other words, is that Art is like receiving the handy-me-downs of clothing from your cousins that they had also received as hand-me-downs from even more distant relatives.
The story of Dorian Grey (Ben Barnes) starts with his commissioning his portrait to be painted by his friend Basil Hallward (Ben Chaplin. At the start of the story, Dorian is an innocent, but is slowly corrupted into decadence by the suave and amoral Lord Henry Wotten (Collin Firth), who finds himself infatuated with Dorian's youth and good looks. Dorian's descent is aided by his discovery that his painting absorbs anything bad that happens to him, giving Dorian access to a seeming fountain of youth. The painting functions as a whipping boy, allowing Dorian to imbibe drugs, drink excessively, and cavort with prostitutes without having to worry about any of the negative consequences of his actions.
The story of Dorian Grey can therefore seen as a response to Plato's challenges to art. The painting by becoming the symbolic embodiment of Dorian Grey's sins, ends up as a better reflection of Dorian Grey's true soul or form, than his physical body. It's almost as if Oscar Wilde was trying to argue that art can act as a deeper and more meaningful mirror of reality than our physical forms are capable of.
As for the 2009 film adaptation, Dorian Grey is fairly well done on the whole. Collin Firth is suitably charming, as he recites Oscar Wilde's dialouge - adopted by for the screen scribe Tony Finlay. Firth gives the best performance in the film, by playing Lord Wotton as a callous libertine who simply does not give a damn about how the consequences of his actions effect other people. Ben Barnes is less successful as Dorian Grey. Barnes is stiff enough in most scenes to be easily mistaken for an actual painting or sculpture. Director Oliver Parker does a good job though, of creating a moody atmosphere and effectively pacing the film so as to generate enough suspense to keep audiences interested.
On the whole, I recommend this adaptation. It's not perfect, nor is it as intense as it could be. However, for a Gothic horror story, it has enough going for it, I believe, to warrant people seeking it out.