Thanks for the link, that was very interesting! The description of "Solaris" as something that has a being-aliveness but which cannot be conceptually grasped is pretty much my idea of it. If can even be said to communicate, it communicates-by-becoming. It does not understand.

It does sound as if the author hadn't seen the movie. I think many reviews at the time didn't like it or get it or misinterpreted it. The finale of the 2002 version isn't optimistic or love-wins; it's very ambiguous I think. In a way, more courageous for it.

But this is down to interpretation. You prompted me to take a look at the script, and it seems that the original drafts vs the movie are quite different.

Gibarian's temporary appearance in the "only choices" scene is less ambiguous in nature, and that key line is missing. It obviously took them a few rewrites to work out what they thought was going on, and eventually took a step back - correctly, I think.

Original version:

After a long beat, Kelvin bolts upright, his mind struggling
to clear.  When it does:

                KELVIN
      Gibarian.

                GIBARIAN
      Leave the light off.

A beat.  Kelvin tries to get his bearings.

                GIBARIAN
      I wish you'd come a little sooner. 
      I might not have had to kill
      myself.

He smiles, looking at Kelvin.

                GIBARIAN
      You think you're dreaming me, like
      you dream her.  Understand
      something: I am the real Gibarian. 
      Just a new incarnation.

                KELVIN
      What do you want?

                GIBARIAN
      You're being tricked.  Sartorius
      picked a fight with you to avoid
      telling you about his idea for
      getting rid of the visitors.  He's
      figured out they're made of
      subatomic particles called
      neutrinos, and he's going to create
      a negative neutrino field.  Twenty
      four hours a day, until they're
      back on Earth.

                KELVIN
      Can it work?

                GIBARIAN
      It can.  Ordinary matter, like
      ours?  Not affected.  Everything
      else, disintegrates.

Kelvin registers this.

                GIBARIAN
      What I'm saying is: Don't trust
      anyone.  Find yourself a weapon of
      some sort.

                KELVIN
      I can trust Rheya.

                GIBARIAN
      You'll end up like me.

                KELVIN
      You're not Gibarian...

                GIBARIAN
      No?  Who am I, then?

                KELVIN
      A puppet.

                GIBARIAN
      And you're not?  Maybe you're my
      puppet.  But like all puppets, you
      think you're actually human.  It's
      The Puppet's Dream.  Wondering if
      they're human!

Gibarian smiles.