A remote differentia distinguishes a species at the level of a more remote genus but does not yet provide its final distinction within the proximate genus.
'Sentient' (ḥassās) is remote with respect to the human species: humans and other animals are sentient, so this feature separates them from some other growing bodies, but not from horses.
Rational — proximate for human
Sentient — remote for human
The distinction depends on the level in the genus–species hierarchy.