Tom Elrod’s review published on Letterboxd :
Finally opened my Blu-ray to re-watch after the news of Hoffman's death. This film pulls off the duet that THERE WILL BE BLOOD sort of attempted but couldn't (Daniel Day-Lewis simply giving too towering of a performance for Paul Dano to compete): Phoenix and Hoffman acting as two men with polar opposite approaches to human interaction. Phoenix's Freddie Quell is all naked emotion, completely unable to think beyond his current desires or frustrations. Hoffman's Lancaster Dodd is purely theatrical, every moment of his life a performance based on some unseen (probably as yet unplanned, except by his wife) grand strategy.
Hoffman perfectly captures the rhythms of a certain type of spiritual leader, those with a missionary or evangelical zeal. I was reminded of youth group leaders, summer camp counselors, and even the pastor from the Methodist church I grew up at. They carry with them an authority that seems to have no doubt behind it - a lack of doubt that makes them seem uncanny, though it's this simulated authority that draws you in - and then every so often they "slip" out of that role into more of a "buddy," chatting about football or playing Nirvana on their guitar. (In the 90s, at least, it was Nirvana.) Dodd does this whenever he asks Freddie for more of his liquor or squints at him and asks, "Where do I know you from?" But of course these slips into informality are also part of the performance. And what makes Hoffman so great is how he invests Dodd with an unyielding sense of exhaustion, that all this acting all the time with everyone is really wearing on him. There are only a small handful of moments where he actually DOES slip, and we see the bitter, angry man within. Once is the great "Pig Fuck" scene; another is when Laura Dern's acolyte presses him about changes in Cause doctrine, causing Dodd to snap, "What do you WANT?"
Hoffman's final scene, where he serenades Freddie with "A Slow Boat to China" and gets all emotional, is, I'm pretty sure, NOT one of those moments. He's still giving Freddie what he wants, which is to feel needed. And I don't think it's the case that Freddie is somehow "over" Dodd or anything at the end, simply that he notices when he's being manipulated and would rather continue doing the manipulating himself, even if just to sand women.
A non-Hoffman moment that seems key: early on, right after the war ends, there's a scene where a room full of veterans are listening to a lecture about all the great things they can now do for their country: start a business, go back to school, etc. They are warned, however, that most people "won't understand" what they've been through. What they aren't told is that they may not understand it themselves. THE MASTER is Freddie's story, about a man who does not re-integrate into American society, who does not contribute anything, who wanders alone but doesn't know why. For a while he spends time with a man who he thinks he has all the answers, but that was obviously never true, and in the end he's still on his own. If Lancastar Dodd is America, then Freddie Quell is us, and there really aren't any Masters anyway.