Somehow it's crime to imprison holy philosopher (10)
I believe the answer is:
empiricist
'philosopher' is the definition.
(empiricist is a kind of philosopher)
'somehow it's crime to imprison holy' is the wordplay.
'somehow' indicates an anagram.
'to imprison' means one lot of letters goes inside another.
'holy' becomes 'pi' (I've seen this in other clues).
'its'+'crime'='itscrime'
'itscrime' with letters rearranged gives 'emricist'.
'emricist' going around 'pi' is 'EMPIRICIST'.
(Other definitions for empiricist that I've seen before include "One believing all knowledge is based on experience" , "Believer that all knowledge is based on experience" , "Philosopher" .)