The person’s reflexive identity feels no change (7)
I believe the answer is:
oneself
'the person's reflexive identity' is the definition.
I know nothing about this answer so I can't tell whether this works.
'feels no change' is the wordplay.
'change' indicates anagramming the letters.
'feels'+'no'='feelsno'
'feelsno' is an anagram of 'ONESELF'.
Can you help me to learn more?
(Other definitions for oneself that I've seen before include "Feels on (anag.)" , "Introvert's study" , "Third person singular pronoun" , "Personal pronoun" , "By this, unaided" .)