Although my question is based on the comic mini-series Infinity Gauntlet issues #1 through 6, I'm open to any and all answers (i.e Movies, other comic books etc. etc.) across the Marvel multi-verse.
It was elegantly presented in the Infinity Gauntlet series how Thanos, after collecting all the soul gems snaps his fingers and destroys half the universe.
Additionally, in the recent movie Avengers: Infinity War,
Thanos does it again! He snaps his fingers and destroys half the universe.
However, one thing is unclear to me. In both cases,
Half the universe is destroyed (or obliterated, or erased from existence).
But who decides which half of the universe should not exist anymore? Does the wielder of the Gauntlet choose, or is the Gauntlet (along with the stones) sentient enough to make the decision?