true self in mahayana is tathata (thusness or suchness)
The term Tathata in the Mahayana tradition is seen as representing the base reality and can be used to terminate the use of words. A 5th century Chinese Mahayana scripture entitled "The Awakening of Faith in the Mahayana" describes the concept more fully: "In its very origin suchness is of itself endowed with sublime attributes. It manifests the highest wisdom which shines throughout the world, it has true knowledge and a mind resting simply in its own being. It is eternal, blissful, its own self-being and the purest simplicity; it is invigorating, immutable, free... Because it possesses all these attributes and is deprived of nothing, it is designated both as the Womb of Tathagata and the Dharma Body of Tathagata
Tathata as a central concept of Mahayana Buddhism, expresses the appreciation of reality within a unique moment. As no moment is exactly the same, each one can be savored for what occurs at that precise time. Tathata is often best revealed in the mundane, such as noticing the way the wind blows through a field of grass, or watching someone's face light up as they smile. Shakyamuni Buddha transmitted the awareness of Tathata directly to Mahakasyapa in what has come to be rendered in English as the Flower Sermon. As Molloy[1]states, "We know we are experiencing the 'thatness' of reality when we experience something and say to ourselves, 'Yes, that's it; that is the way things are.' In the moment, we recognize that reality is wondrously beautiful but also that its patterns are fragile and passing."
1^ Molloy, M. "Experiencing The World's Religions." page 130. Mayfield Publishing Co., 1999.
Within the Mahayana branch of Buddhism, there exists an important class of sutras (influential upon Ch'an and Zen Buddhism), generally known as Tathagatagarbha sutras ("Buddha-Matrix" or "Buddha-Embryo" sutras), a number of which affirm that, in contradistinction to the impermanent "mundane self" of the five "skandhas"(the physical and mental components of the mutable ego), there does exist an eternal True Self, which is in fact none other than the Buddha himself in his ultimate "Nirvanic" nature. This is the "true self" in the self of each being, the ideal personality, attainable by all beings due to their inborn potential for enlightenment. The "tathagatagarbha"/Buddha nature does not represent a substantial self (atman); rather, it is a positive language and expression of "sunyata" (emptiness) and represents the potentiality to realize Buddhahood through Buddhist practices; the intention of the teaching of 'tathagatagarbha'/Buddha nature is soteriological rather than theoretical.


