According to some scholars, the Tathāgatagarbha does not represent a substantial self ("ātman"); rather, it is a positive language expression of emptiness ("śūnyatā") and represents the potentiality to realize Buddhahood through Buddhist practices; the intention of the teaching of Tathāgatagarbha is Soteriology rather than theoretical. This interpretation is contentious. Not all scholars share this view. Michael Zimmermann, a specialist on the "Tathagātagarbha Sūtra", writes for instance: "the existence of an eternal, imperishable self, that is, buddhahood, is definitely the basic point of the "Tathagatagarbha Sutra".