The Difference Between the Mindless Concentration (asaṃjñi-samāpatti) and the Samādhi of Suchness (tathatā-samādhi)

The meaning of the mindless samādhi is dwelling within a state of meditative concentration without thought or conception, having nothing to attend to, with nothing whatsoever on one's mind, where the mind consciousness does not engage in contemplative observation or thinking—just like the state of "inwardly guarding a leisurely ease" that the World-Honored One spoke of in the Śūraṅgama Sūtra. All of these are states in which the mind consciousness is idle. Some people mistakenly take this state to be the true suchness (tathatā) that is free of thought and conception, and believe they have realized the samādhi of true suchness.

In fact, true suchness originally has not a single thought or conception, whether or not one cultivates meditative concentration—it is always so. Therefore the state of true suchness never changes. But the mind consciousness's freedom from thought within meditative concentration is something cultivated, something that did not exist before and arises later; and what arises can later cease—it will sooner or later disappear. A dharma subject to arising, ceasing, and change is not the unborn and unceasing true suchness, and thus it is not equivalent to the state of the samādhi of true suchness.