Four answers to the same question
A string quartet has no conductor to settle every decision. Balance, articulation, timing and character emerge through listening and discussion. The goal is not to erase four personalities, but to let them form an interpretation none of us could produce alone.
Sometimes a passage changes through words; sometimes one person plays it differently and the room immediately understands. The most useful rehearsals move continuously between analysis and instinct.
An interpretation is never finished
Concerts do not simply reproduce the rehearsal. A hall, an audience and the energy of a particular evening alter proportions and invite new responses. Rehearsal creates the shared language that allows those changes to happen without losing direction.