Life perhaps encapsulating one’s feeling (9)
I believe the answer is:
sentience
'feeling' is the definition.
(something sentient is conscious or feeling)
'life perhaps encapsulating one's' is the wordplay.
I cannot really understand how this works, but
'one' could be 'i' (Roman numeral) and 'i' is found within the answer.
'life perhaps' could be 'sentence' (I've seen this before) and 'sentence' is located in the leftover letters.
No letters remain.
This may be the basis of the clue (or it may be nonsense).
Can you help me to learn more?
(Other definitions for sentience that I've seen before include "awareness" , "Feeling" , "Ability to feel or perceive" , "Ability to feel things" , "Consciousness -- ten nieces (anag)" .)