The quintessential Ingmar Bergman films, to me - the once that most sum up all of his strengths as a film director, his preoccupations as a writer, and his function in the ecosystem of art cinema - are a set of three movies he made in the early 1960s, right when his international visibility was peaking and plateauing: Through a Glass Darkly, from 1961, and Winter Light and The Silence, both from 1963. At the time, he identified these as a loose thematic trilogy, centered around the question of whether God exists and is ignoring us, or if God no longer exists or never did. Later on, he walked back form this idea, but the damage was done, and ever since the mid-'60s, referring to these movies as a trilogy - the Faith Trilogy or the God's Silence Trilogy are the two main ways I've heard it referred to* - has been pretty much the reflexive thing to do.

I've also heard the films called the Chamber Drama Trilogy, and I think this much less common name gets at why, pace Bergman, it makes sense to bind them together. These are fundamentally different films from what he had been up to before: by and large, Bergman had kept his work as a theater director and his work as a film director separate, but these three "chamber films" all feel like some jarring hybrid of the two forms, almost consciously anti-cinematic in a way, despite all three having distinctly and necessarily cinematic aesthetics. In particular, they are all massively concerned with the human face in close-up; by 1961, already a long-established favorite device of the director, but the style reaches new extremes in these movies. They are the point he goes from using close-ups as a tool, moving us in close to the characters in a probing, hushed intimacy that only a film camera can permit, to using close-ups effectively as a medium in and of themselves, to be manipulated and controlled and molded. It's the basic unit of most of Bergman's best films for a 12-year span, the same 12-year span where he reigned as one of world cinema's titans.

Of course, nobody would have known any of this in '61, when Through a Glass Darkly was new, and there was no trilogy. From this vantage point, all we can really say is that, having established himself about as securely as it is possible for a filmmaker to be secured, the director took the probably inevitable step of finally just making an unabashed August Strindberg knock-off. Strindberg comparisons had followed Bergman all through his career, and he had directed a few stage productions of Strindberg plays; it seems to me that things came to a head with the 1960 television version of The Storm, the first time Bergman staged a Strindberg piece around a film camera. While I can't imagine he was thinking of it in such terms at the time, we can look at that production as the proof-of-concept, that a chamber drama could work onscreen just as well as onstage. Through a Glass Darkly is thus the attempt to write a chamber drama to make use of the affordances of cinema, rather than retrofit a stage play.

At which point, need I define chamber drama? We're not going to get very far if we're not on the same page, so perhaps I had better. In the most mechanical definition, a chamber drama is a small-scale dramatic narrative that can take place in a single location with little in the way of a detailed set or too many props; it also has very few characters. I do not believe it is strictly a requirement of the form that it be a psychological study of one or more of those characters and their interactions, but that's true of every example I've seen. The name comes by analogy to "chamber music" - pieces played by just a few musicians in a relatively small room - and Strindberg, at least, seems to have taken that analogy at least somewhat literally. So too did Bergman, who referred to Through a Glass Darkly as a "string quartet", with each of the film's four actors providing a different piece of the overall melodic shape of the thing.

The quartet in front of us at the moment are a family who have just gathered together on a quiet island, in part because Karin (Harriet Andersson) has just been released from a mental hospital, and needs a place to get her feet back underneath her. It's not actually clear that was a driving priority for her father, David (Gunnar Björnstrand), who has just returned from Sweden from a business trip abroad, and doesn't seem likely to stay for all that long before the next trip. Karin makes excuses for this and her husband, medical doctor Martin (Max von Sydow), has enough wearied superiority to be unsurprised and thus not care, but David's teenage son, Karin's brother Minus (Lars Passgård) is very clearly wounded by his father's indifference.

We might go so far as to call it a quintet, and add as a fifth player the island itself; "It's like [location] is a character!" is one of the most derided statements in film criticism for a good reason, but there have been very few movie locations like Fårö, the island off the southeastern coast of Sweden where Through a Glass Darkly was shot. It wasn't Bergman's first choice; he wanted to shoot on the Orkney islands, northeast of Scotland. Svensk Filmindustri wanted something closer to home, though, and it was apparently cinematographer Sven Nykvist who first suggested the small, thinly-inhabited Fårö. For Bergman, it was love at first sight: he relocated his home to Fårö and shot several movies there, living on the island until his death in 2007 (give or take a self-imposed exile over a tax dispute). And there's no denying the extraordinary presence that the place has. Under Nykvist's eye, the island feels beautifully barren, a rocky place that is ultimately indifferent to its human inhabitants, rather than actively hostile, but certainly not welcoming, and not a place where people can comfortably exist without effort.

Through a Glass Darkly covers approximately a 24-hour period during the time of summer when Sweden's nights are more like very heavy dusks, and this is very much part of the narrative strategy: the middle part of the film, at the dead of "night", finds Karin feeling restless and too alert, and we follow her around the inside of the house in a soft gloom that does, in fact, feel like it's just a little too bright to sleep through, and it is, in fact, likely that you brain would start to go a little haywire with seeing and hearing things that don't mean what you supposed, especially if your brain was a little haywire to begin with. This is the main thrust of the plot: Karin starts to get a little weird, apparently hearing message from God - or something she interprets to be God, at least. And this throws the three men in various kinds of disarray. The family situation as the film starts is a bit too sad and pathetic and petty to earn a word like "fraught", but it is at least tense and tetchy; Karin's apparent break from reality is just the stimulus that kind of situation needs to well and truly erupt, though it erupts slowly and quietly, tamped down by the same shadowy hush that has squatted over the entire film.

Might as well get my big problem out of the way first, especially since it's not a very big one. So it's a string quartet, and I don't think it's hard to map them onto the instruments in question. Karin is the first violin, dominating and controlling our experience of the piece, and Minus is the second violin, following and amplifying her. David is the viola, stronger bodied and providing the context in which the violin's melody emerges. Martin is the cello, sturdy and heavy and fundamental, the soberest part of the piece, in the background. And you need a cello, of course, but in the particular case of Through a Glass Darkly, it feels a little bit like Bergman knew that three characters would feel imbalanced but four would feel just right, and so he grabbed for Martin more because he wanted a full set than because he'd written a good cello part. Von Sydow is more than actor enough to have gravity and weight in the role, but when it comes right down to it, I don't know what Martin does for the film that isn't strictly functional.

Then again, with Karin, David, and Minus, we have plenty of phenomenal character building, with acting to match it. David is a brilliant, unexpected role for Björnstrand, who largely played affable, distractable types; he was by training best at mannered comedy, and Bergman generally used him as such, whether as the bracing comic relief of The Seventh Seal or the warmest and silliest part of The Devil's Eye. He brings that same genial backbone to David, but this is a fundamentally different part: the paterfamilias is a distant, thoughtless figure, uninterested in the continued functioning of his children's lives, though he is quite happy with the trappings of upper-middle-class family life and going through the motions of being a kind and loving authority. It is, in fact, at least partially implied that his general lousiness as a person is on the line of descent that ends at Karin's God-psychosis. And this hard-edged character gives Björnstrand some amazing notes to play, ending in his best performance in a Bergman film up to that point: his David is both distant and distracted and aware that he's distant and distracted but not really torn up too much about it. And yet, as the film progresses, he has to convince us that this character is, in fact, growing more concerned about his daughter's wellbeing and aware of his own complicity in her state, while also making it seem like he's going to try to change but not be very good at it - his delivery of his final line is a masterpiece of trying to be sincerely kind and good but having it come off more like play-acting and kindness. It's a hell of a performance for a hell of a part.

It's Karin's film, though, and Andersson's. She didn't want the role, her first appearance in a Bergman film in six years and after their love affair had ended; she wasn't convinced she could play it. But the director insisted that she could, and so gifted her with a role that led to her giving one of the best performances of the 1960s. Obviously, the role is showy: a madwoman trying to keep her madness stuffed down is a plum role for anybody, even when the tone of the script is so coolly anti-melodramatic as we see in Through a Glass Darkly. Part of what keeps it cool is that Andersson isn't overplaying things: she has latched onto the hints in the screenplay that Karin is a mystery to herself every bit as much as to the three men, and so plays things with an inward-looking quiet: she doesn't mumble, as such - the film's arch theatricality would permit no such thing - but she gives the impression of mumbling, of being folded in on herself.

This all feels like it's leading to the point where it erupts in the last 20 minutes, when we arrive at what I will happily call the single best scene in a Bergman film to this point: the discovery of just what Karin is seeing and hearing when she claims to see and hear God, and how that is attached to her ambivalent relationship with sex (she has, up to this point in the film, rebuffed a not-trying-very-hard Martin, seemingly out of confusion as to why he'd want to, and had sex with her brother). Viewing the piece strictly as a character drama, the sex part probably matters more - it is certainly the more visceral and horrifying part, with Andersson's screwed-up, very precise and thoughtful description of how God tried to assault her providing the first great "watch somebody talk about something so intensely you can almost visualise it" scene in Bergman, as well as one of the most purely horrifying moments in the director's canon. But I have always responded more to her mesmerised description of seeing God, which feels like it opens up the film beyond being a character drama about these four people, making it a work of the desperate atheistic theology that Bergman's very next film would take to such guttural depths of human pain. Less articulate, less tightly-wound; Karin is not a very articulate or well-machined character. And this gives the climax of Through a Glass Darkly a raging quality that Winter Light evades, love it as much as I do.

The ending thoroughly overwhelms the rest of the film, I think; one can almost see the movie solving its major problem as it goes along, and having solved it about 70 minutes in, using it to fullest advantage. It seems to me like the main goal of the film was finding a way to combine Bergman's two loves, theater and film, in one form that uses the strengths of each. Hence my feelings that this is very much a film made in the wake of The Storm, where he started playing around with blocking the actors and positioning the camera to find a visual analogue to the effect of live theater, especially the charged sense of emotional presence and intimacy. None of the things he played with in The Storm really show up in Through a Glass Darkly, as it so happens, and I find myself wondering how much of that is because Fårö (especially Fårö seen through Nykvist's noir-like cinematography, emphasising every crag on every rock) did so much of the work for him. It is very much a location that you would almost be embarrassed to use to symbolise internal torment, it's so metaphorically perfect: bare rock thrusting up through meager grass, dramatic and beautiful, but also cold and stony and hostile to humans. And the house, captured in gloomy charcoal greys that never quite resolve into pure black, also gets much of the point across as well. Basically, Bergman had experimented with close-ups in the very near past, and would pick up those experiments in the very near future, but he's not experimenting here: he's just using close-ups as tools for getting into Andersson's remarkable performance.

To be clear: these are the right tools, and he's using them superbly. Bergman's filmmaking style in the '60s and into the '70s would become almost dangerously dependent on peering intently at an actor's face while they methodically work through his densely-worded monologues; somehow, despite the wide margin for error, this almost never went wrong for him. And this is basically the film where he starts that project, spending most of the running time looking at Andersson's face, trusting and knowing that she has it inside of her to give the small inflections to her eyes, her mouth, and her words that will let us into her character. Every other actor gets some of this, and it is maybe part of the film's commentary on David that Björnstrand gets the fewest, and tends to have to share them with one of the other three. But it's a strategy for creating extra intimacy within the already intimate script, and it keeps paying off right to the final line, which is a perfect collage of Passgård's amazed expression and the rough seas that opened the film and have run throughout it, immediately suggesting the distorted, unclear reflection of the Biblical quote after which the film was titled (in Swedish, it's As in a Mirror; either way, it's a reference to chapter 13, verse 12 of the first letter to the Corinthians - the little speck of darkness in the famous lines on the nature of love).

It's an elegant, troubling, terrifying piece, weakened only slightly by how much more interesting the last third is than the first two thirds, and by an ending that Bergman later felt was probably trying to be comforting and optimistic more than the film justified (it's not very optimistic, to be sure. But this is, after all, a movie about the revelation that God is, perhaps, not love, and that God's silence may be much preferable to God's presence; the mere suggestion that David and Minus are going to forge a closer relationship, however ambivalently Björnstrand plays it, feels like it's doing exactly the opposite of that). And the criticism that Bergman's characters talk about themes rather than themes naturally expressing themselves (a criticism that I think was not very common at the time these were new, but has become probably the go-to complaint about his work) starts to become very easy to make starting right here. Still, this is to me the opening salvo in the single richest body of work to come out of the Golden Age of European art cinema in the '60s.

*The Criterion Collection played it safe and boring, releasing the three films on DVD as a box set titled A Film Trilogy by Ingmar Bergman.