The question whether intelligent life exists elsewhere in the universe is certainly imprecise, because we are not sure how different from us something might be and still count as “intelligent life.” Yet we cannot just decide to define “intelligent life” in some more precise way since it is likely that we will find and recognize intelligent life elsewhere in the universe only if we leave our definitions open to new, unimagined possibilities.
Your task
Describe how the argument proceeds — the technique it uses to reach its conclusion.
Common trap
Answers that describe a method the argument doesn't actually use.
Winning move
Track the role each statement plays, then match that to the choice describing the same moves.