### Clue: Posh fellow probes possibly this non-believer (8)
### Answer: HUMANIST 
 ### Explanation: Definition: non-believer
 [ U(posh;upper-class) + MAN(a fellow) ] **contained in**(probes) **anagram of**(possibly) THIS.
Defn: One who believes that people's spiritual and emotional needs can be satisfied without having to believe in a god or religion. (Thus, not exactly a non-believer.)