Philosopher

Someone who studies or writes about the meaning of life

EX: Confucius was a Chinese philosopher

Merriam-Webster Online Dictionary
philosopher (noun)
1.
a) a person who seeks wisdom or enlightenment - scholar thinker
b) a student of - philosophy
2.
a) a person whose perspective makes meeting trouble with equanimity easier - philosophical
b) an expounder of a theory in a particular area of experience
c) one who - philosophizes