The Śūraṅgama Sūtra presents mental purification as the gradual clarification of an originally pure, luminous awareness that underlies all changing thoughts and perceptions. It distinguishes carefully between this unmoving “true mind” or Buddha-nature and the fluctuating stream of discriminating consciousness that chases after forms, sounds, and other sense-objects. Impurity, in this vision, does not belong to the true mind itself; it arises from mistaking the conditioned flow of thoughts, emotions, and sensory experiences for a real self and clinging to them as “I” and “mine.” Purification, therefore, is not the acquisition of some new state, but the removal of obscurations so that the mind’s inherent clarity can be directly recognized.

The text emphasizes a meditative turning away from outward dispersion toward the very source of awareness, often described as “turning the light around” or “perfect penetration” through a sense faculty, especially hearing. Instead of following sights, sounds, and mental images, attention is directed back to the knowing itself, “observing the observer” rather than its objects. As this inward turning stabilizes, attachment to the six sense-objects and their corresponding consciousness streams is progressively loosened, and the discriminating, conceptual activity of mind begins to fall silent. In this way, the practitioner learns to discern the unchanging “seeing essence” from the changing field of experience, and the grip of false identification is slowly released.

Within this contemplative process, the sutra highlights the importance of recognizing the illusory and impermanent nature of mental fluctuations and sensory appearances. By directly examining how thoughts arise and cease, and seeing that they lack any fixed, independent essence, their compelling power is weakened. The practitioner moves through stages: first noticing the turbulence of thought, then seeing its insubstantiality, then entering deeper samādhi in which subject–object duality loosens and eventually dissolves. As attachment to sensory experience, egoic identity, and even subtle spiritual attainments is relinquished, the mind’s original purity—described as the “Treasury of the Thus-Come-One”—stands revealed, not as something newly produced, but as what was present all along once defilements are removed.