Acting and performing―used interchangeably in the world of film and theatre―are not the same thing and shouldn't be seen as such. Acting is only performing in the most general definition―doing something in front of an audience―and performing in a film is only acting in the sense that one is playing a role. Clearer distinctions should be made between the words in order to define two similar sounding things that are actually quite different. Let the hair splitting begin!
The best performance I saw last year was
Toni Servillo in The Great Beauty.
The best acting I saw was done by
Adèle Exarchopoulos in Blue Is the Warmest Color.
Whether or not you agree with these particular choices is of no consequence. I'm only interested in what makes them different―a difference which is distinct enough to get some sense of from Exarchopoulos and Servillo's respective expressions. Servillo's is unambiguous, forceful, confident, and projecting an essence. Exarchopoulos expresses more ambiguity: shyness, slight embarrassment, mild awkwardness―yet she's also amused.
But let's not read too much into this.
* * *
James Cagney and Henry Fonda. Who's the actor and who the performer? Assuming you've seen at least a couple of films starring each, this question seems easy. Why? Because we notice a difference in what each does. One could boil it down to differing styles of acting, yes, but I think a more concrete distinction―one involving completely separate categories―is more beneficial since many of those who excel in one "type" of acting are incapable of greatness in the other. The skills required are as different as their intended effects. (Just to make sure we're on the same page: Cagney was the performer, Fonda the actor.)
Performing is more about energy, presence and physicality. Acting is more about realism, subtlety, ambiguity, layers and understatedness. A great performance is usually archetypal. Rather than playing a human being, the performer plays certain emotions or feelings or attitudes made flesh. This doesn't mean that a performance can't be multidimensional, only that it's the kind of complexity that would be more at home in a Greek comedy or tragedy than in a play by Eugene O'Neil. Or in a film by Roy Andersson rather than in one by a young Rossellini.
Performing is breakdancing, acting is ballet.
However it might sound, I am not equating extroverted characters with performing and introverted characters with acting. Gene Hackman's character in Night Moves is outgoing (however misanthropic) whereas Marie Falconetti's Joan of Arc is deeply introverted. Yet both are examples of great acting. Introverted characters can also be performed (e.g: Buster Keaton, Jacques Tati's Hulot). The difference between acting and performing is not in the role or personality of the character but in how it's played.
And just to be clear, I'm not making any qualitative comparison between acting and performing. They're simply different. Different enough that, when "acting" awards are given, there should be two separate categories: one for Best Actor and one for Best Performer.
Examples will provide a more fruitful, concrete and (hopefully) fun exploration.
Daniel Day Lewis gives a performance in There Will Be Blood and acts in The Ballad of Jack and Rose.
Tom Hardy is performing in Bronson and acting in Lawless.
The young Al Pacino was a great actor. Old Al Pacino is a mediocre performer.
(Did I say mediocre? I meant awful.)
The Marx Brother's were strictly performers. (Great ones.)
Humphrey Bogart was an actor who tried to perform.
Jack Nicholson gives a great performance in One Flew Over the Cuckoo's Nest and shows himself to be capable of great acting in Five Easy Pieces. But primarily he's the opposite of Bogart: a born performer who tries to act.
Carey Grant was a great performer.
Michelle Williams is one of the great living actors.
Martin Donovan and Chris Eigeman are performers.
In the film Nebraska, June Squibb is performing while Bruce Dern is acting.
Sometimes the character being played is a performer in some sense but the person playing that character is still acting:
R. Lee Ermey (Sgt. Hartman) is giving a performance in Full Metal Jacket.
Ivan Dixon is acting in Nothing But a Man.
Great performances: Jack Lemmon and Tony Curtis in Some Like It Hot.
Great acting: Humphrey Bogart in The Treasure of the Sierra Madre.
Nicole Kidman in Dogville? Great acting.
A performance: Bob Odenkirk as Saul Goodman in Breaking Bad.
Orson Welles was a performer, Montgomery Clift, an actor.
Anthony Hopkins' Hannibal Lector is a performance.
One of the things that distinguishes Fellini's early work from his later work: his characters go from acting to performing.
Finally, an example of each at their very highest incarnations.
A Great Performer:
A Great Actor:
I tried to compare various styles and periods of "acting"―old Hollywood, theatrical, method, etc.―to show that acting and performing are not actually stylistic differences at all but rather differences in type. Yes, it's all "acting" so one can say that any distinction being made is pointless or unnecessary. But I think the distinction is clear enough to merit drawing a line, however faint.
It's also fun to discuss this with friends after viewing certain films, or just to compare examples. For instance, what exactly is the great Timothy Carey doing in the clip below? I can't decide. He seems to vacillate seamlessly between acting and performing. Maybe it's better just to call it Lightning in a Bottle.