Defining characteristic of the Jīva (soul) JīvatvaThe mode of the soul as living being, Caitanya (consciousness or sentience).
jive ṇaṃ sauṭṭhāṇe......spurisakkāra-parakkame
āyabhāveṇaṃ jīvabhāvaṃ uvadaṃsatīti vattavvaṃṃ siyā..
jīvabhāvaṃ tijīvatvaṃ caitanyam.
(Bhaga 2.136 Vṛ)