There’s a lesson to be learned first from the philosopher (8)
I believe the answer is:
moralist
'the philosopher' is the definition.
(moralist is a kind of philosopher)
'there's a lesson to be learned first' is the wordplay.
'there's a lesson to be learned' becomes 'moral' (I've seen this in another clue).
'first' becomes 'ist' (ist resembles 1st).
'moral'+'ist'='MORALIST'
'from' acts as a link.
(Other definitions for moralist that I've seen before include "preacher" , "Good teacher" , "principled person" , "One teaching right and wrong" , "Ail storm (anag)" .)