Belief shattered with ends justifying means? (10)
I believe the answer is:
'justifying means?' is the definition.
(that which can be defended or justified)
'belief shattered with ends' is the wordplay.
'shattered with' indicates anagramming the letters.
'belief' mixed up with 'ends' gives 'DEFENSIBLE'.
(Other definitions for defensible that I've seen before include "Not at all easy to comprehend" , "justifying the means?" , "can be justified by argument" .)