What do you call a person who has the ability to question and is curious about right things?

Solution 1:

perspicacious definiton:

Having a ready insight into and understanding of things.

Solution 2:

A person to whom seeking out cavils in other people's statements and arguments is a source of rich joy is called:

• a pedant: a person who overemphasizes rules or minor details
• a pharisee: a sanctimonious, self-righteous, or hypocritical person

A person who questions other people's arguments and insists on finding his or her own answer can be called:

• an explorer: a person who investigates unknown regions, not necessarily geographical

• a pioneer: one who is first or among the earliest in any field of inquiry, enterprise, or progress

• a pathfinder: a person who finds or makes a path, way, route, etc.

• a trailblazer: a pioneer in any field of endeavor

All definitions are from The Comprehensive Online Dictionary