Buddha." According to the Śūraṅgama, the worldly mind "is the mind that is the basis of death and rebirth and that has continued for the entirety of time...dependent upon perceived objects." This worldly mind is mistaken by sentient beings as being their true nature. Meanwhile, the "pure enlightened mind" is the underlying nature of all dharmas (phenomena). It is the ultimate reality which is also enlightenment, which has no beginning. It is the original and pure essence of nirvana. The true awakened mind is an unchanging awareness that remains still and independent of all sense objects, even while the discriminating mind changes. The pure mind then is the essential nature of awareness, not the ordinary awareness which is distorted and diseased. This theme of the everlasting true mind which is contrasted with the samsaric mind is also a common theme of the Mahayana Awakening of Faith treatise. Buddha-nature The "everlasting true mind" is associated with the Mahayana teaching of tathāgatagarbha or buddha-nature. Rounds and Epstein explain the Śūraṅgama's conception of the tathāgatagarbha, the "Matrix of the Thus Come One", as follows: Thus, according to the Śūraṅgama Sūtra the "buddha-womb" or "buddha-essence" is source of mind and world. This buddha nature is originally pure enlightenment, however, due to the deluded development of a subject-object separation, the whole world of birth and death arises. Meditation practices The Śūraṅgama Sūtra teaches about the Śūraṅgama Samādhi (the "meditative absorption of the heroic march"), which is associated with complete enlightenment and Buddhahood. This samādhi is also featured extensively in the Śūraṅgama Samādhi Sūtra. It is equally praised in the Mahāparinirvāṇa Sūtra, where it is explained by the Buddha that this samādhi is the essence of the nature of the Buddha and is indeed the "mother of all Buddhas." The Buddha also comments that the Śūraṅgama Samādhi additionally goes under several other names, specifically Prajñāpāramitā ("Perfection of Wisdom"), the Vajra Samādhi, the Siṃhanāda Samādhi ("Lion's Roar Samādhi"), and the Buddha-svabhāva. The Śūraṅgama Sūtra contains various explanations of specific meditation practices which help one cultivate samadhi, including a famous passage in which twenty five sages discuss twenty five methods of practice. The main intent of these various methods is to detach one's awareness of all sense objects and to direct awareness inward, to the fundamental true nature. This leads to the experience of the disappearance of everything and finally to illumination. The most well known part of