' Śūraṅgama Sūtra '
"The Buddha then compounds his cousin's confusion by stating that there are fundamentally two kinds of mind:
1. First, the ordinary quotidian mind of which we are aware and which is entangled, lifetime after lifetime, in the snare of illusory perceptions and random thoughts;
2. And second, the everlasting true mind, which is our real nature, and which is the state of the Buddha."
" Ananda, what are the two fundamentals?
The first is the mind that is the basis of death and rebirth and that has continued for the entirety of time, which has no beginning. This mind is dependent upon perceived objects, and it is this that you and all beings make use of and that each of you consider to be your own nature.
The second fundamental is enlightenment, which has no beginning; it is the original and pure essence of nirvana. It is the original understanding, the real nature of consciousness. All conditioned phenomena arise from it, and yet it is among those phenomena that beings lose track of it. They have lost track of this fundamental understanding, though it is active in them all day long, and because they remain unaware of it, they make the mistake of entering the various destinies."