It has little voice to study organised knowledge (10)
I believe the answer is:
conscience
'it has little voice' is the definition.
The definition suggests a singular noun which matches the answer.
'study organised knowledge' is the wordplay.
'study' becomes 'con' (con can informally mean to study).
'organised knowledge' becomes 'science' (I've seen this before).
'con'+'science'='CONSCIENCE'
'to' is the link.
Can you help me to learn more?
(Other definitions for conscience that I've seen before include "Inner voice" , "having moral standards" , "morals" , "Sense of morality" , "Hamlet blamed for cowardice" .)