Ian McKellen did not receive an Oscar nomination for portraying Kurt Dussander who goes by the name Arthur Denker in Apt Pupil.
Ian McKellen actually shared a few of his wins from critic groups for Gods and Monsters with his performance in this film. Although there was likely no doubt that McKellen would be recognized for his portrayal of the troubled James Whale rather than his performance as a man who calls himself Arthur Denker because he is actually a Nazi war criminal by the name of Kurt Dussander. The high school student Todd goes to Dussander, after doings some research to identify him completely, to hear a first hand account of the Nazi's brutality. McKellen effectively creates not only the Nazi but the old man in Dussander. McKellen is actually playing a much older age, but you would not notice as McKellen so naturally infuses the physical mannerisms of seventy year old into his performance. McKellen's German accent also always feels right for the character and helps amplify its past by having an innate cruelty just in his voice.
There are kinda two sections of this performance so it is best to start with the first half where he portrays a more realistic depiction of the character as the film takes a less absurdest approach. McKellen is terrific in the earliest scenes where Todd is prodding him for the information about his days as an executioner. McKellen is great because he does not portray Dussander as gloating over his accomplishments nor does he portray any guilt in his voice either. McKellen instead plays Dussander's reflections as bluntly as possible of a man recalling events in his past that are said and done. He's not proud of them but he's not sorry for them either. The strongest emotion that McKellen exudes in the same is an exasperation not over having to recall a bad memory, but rather the exasperation of being forced to tell his stories by some young fool. McKellen actually makes these moments the most cruel as Dussander relates his massacres as merely something he did.
One relatively brief but fantastic scene for McKellen is when Dussander visits Todd's family for dinner one night. McKellen portrays the manner of Dussander brilliantly as he creates the facade of just a nice old man who actually is fairly likable. This scene is important for McKellen as he uses to show exactly how Dussander could have avoided capture for so long, and the act he would have been putting for many years. McKellen on this side of things brings out an earned warmth in his portrayal of Dussander. McKellen is good as he leaves a question to the warmth when Dussander portrays it as he never let's on if Dussander honestly will give a loving embrace or perhaps stab someone in the back. McKellen creates the deception of Arthur Denker incredibly well as he brings a danger of his personality as he so artfully hides the evil behind the face of potentially nice old man or even a possible mentor.
Of course Bryan Singer is not a master of tone and there arrives a problem as he takes such a straight approach to the film even though the writing forces the story to go down an absurdest path. The film and Renfro stumble very badly due to this but one man does not and that is Ian McKellen. McKellen apparently seemed to understand the material better than anyone else as he switches his performance accordingly into a darkly comic portrayal of Dussander. At this point McKellen starts to play the part with an evil glee as Dussander controls the boy but also chooses to help him achieve at school. McKellen takes revels in his performance as he brings to life the Nazi inspirational teacher in quite the entertaining fashion. McKellen is very enjoyable to watch as he has a tremendous amount of fun in the part, which he adapts into a more maniacal villain fitting to the film that probably should have been made out of the material.
I have admit I did not even feel a disconnect between the two sides of McKellen's work really as he does slowly alter into the other path as it becomes obvious where the story is going. The early scenes McKellen gives a performance that would not be out of place in a film like Schindler's List and in the later scenes McKellen's performance would be a great fit for Marathon Man or The Boys From Brazil. It is rather funny how much McKellen seems to have a better grasp on the tone of the material than Bryan Singer does. Even though there is an obvious problem here but I can't blame McKellen for his work. The early scenes that are so serious in terms of the writing would have been wrong for a Dr. Szell type approach, but the later scenes which are written as an insane horror story would have been wrong for an Amon Goeth approach. I thought McKellen gave two great performances, it would have been nice if there was a film to go along for each, but that's not his fault.