+1
The characters and the actions in the movie aren't meant to be fully understood.
I'd definitely agree with you on that. I think one of Persona's central themes is the manner in which people hide parts of themselves from those around them, so I guess it would make sense that the characters remain somewhat ambiguous. I'm fairly certain that Alma and Elisabet are the same person, but I don't think I'll ever know which is true: that Alma represents Elisabet's inner self or that Elisabet represents Alma's inner self.
That's a valid interpretation. Another interpretation is that they may be two individuals, but are the same on a deeper psychological level. Perhaps the film implies that all personas are masks covering an essential oneness of human beings in general, and those two are a particular example of that. I've also read of an interpretation that Elizabeth represents Bergman's silent God.
The greatness of Persona for me is that it doesn't clearly distinguish between what's meant to reflect "real life" and what's meant to be purely symbolic...
It's postmodern so you're all correct, in a way.
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"Don't be so gloomy. After all it's not that awful. Like the fella says, in Italy for 30 years under the Borgias they had warfare, terror, murder, and bloodshed, but they produced Michelangelo, Leonardo da Vinci, and the Renaissance. In Switzerland they had brotherly love - they had 500 years of democracy and peace, and what did that produce? The cuckoo clock."