We should always question what we think we know. So, is there a word that describes the act of questioning one's beliefs/values/personal philosophy? Can you say, this person should be more (insert word here)?
As in: OED
This person should be more introspective.
Having the quality of looking within; examining into one's own thoughts, feelings, or mental condition, or expressing such examination; of, pertaining to, characterized by, or given to introspection. introspective psychology, psychology based on introspection and on the direct observation of one's own mental states.