What Is Samadhi?

Samadhi is a Sanskrit term meaning concentration. Within samadhi, there are states of meditative absorption (dhyana) and varying degrees of wisdom. If wisdom is shallow, samadhi primarily manifests as a state of concentration. If wisdom is profound, it becomes a state of equipoise where concentration and wisdom are equally held.

The levels of Buddha-Recitation Samadhi differ. Buddha-Recitation Samadhi primarily focused on concentration is achieved by orally reciting the Buddha's name to enter absorption. Whether walking, standing, sitting, or lying down, one continuously recites the Buddha's name. Ultimately, it reaches a state of "reciting without reciting," where the sound of the Buddha's name ceaselessly reverberates in the mind and ears. Even if one tries not to hear it, it is continuously audible.

Buddha-Recitation Samadhi with equipoise of concentration and wisdom attains the Patience of Non-arising (anutpattikadharma-ksanti) and the Patience of the Non-arising of Dharmas. For instance, practices like visualizing the Buddha's image or contemplating the Buddha begin with oral recitation and mental recitation. Ultimately, the apparitional state (pratibimba) manifests, concentration-produced phenomena appear, the principle of non-arising is realized, and one clearly understands the self-nature Buddha.

After successfully cultivating the Meditation on Impurity and the Skeleton Visualization, one also attains a state of samadhi characterized by equipoise of concentration and wisdom. Concentration is the state of one-pointedness, attainable at the First Dhyana and above. Wisdom is the realization of non-arising, knowing the impurity of the physical body, the selflessness of the five aggregates, resulting in the Third or Fourth Fruition. This is also the Śrāvaka's Samadhi of Emptiness. The apparitional state manifests, and concentration-produced phenomena appear.

Successfully cultivating the Four Foundations of Mindfulness also results in the Śrāvaka's Samadhi of Emptiness, characterized by equipoise of concentration and wisdom, leading to the attainment of the Third or Fourth Fruition.

Mahayana samadhis include the accomplishment of Buddha-Recitation Samadhi and the Sixteen Contemplations from the Sutra on the Contemplation of Amitāyus, both characterized by equipoise of concentration and wisdom. Without samadhi, there is no concentration; without concentration, the wisdom of contemplation cannot be achieved. Within these samadhis, concentration often predominates over wisdom.

In Mahayana Chan (Zen) investigation, at the moment of breaking through (can tou), one also enters a state of samadhi possessing both concentration and wisdom. If concentration is shallow, wisdom is shallow, leading only to the Seventh or Eighth Bhūmi (Stages of Abiding). If concentration is deep, wisdom is deep, enabling one to reach the First or Second Ground (Bhūmi). The mind abides in the emptiness of the Tathāgatagarbha. The five aggregates themselves are the empty Tathāgatagarbha. Walking, standing, sitting, and lying down are as if within the Tathāgatagarbha, devoid of the "I" of the five aggregates.

When Śrāvakas engage in contemplative investigation to sever the view of self, samadhi also manifests, possessing both concentration and wisdom. Shallow concentration results in shallow wisdom, leading only to the First or Second Fruition. Deep concentration results in deep wisdom, enabling the attainment of the Third or Fourth Fruition. The mind abides in the Samadhi of Emptiness where the five aggregates are without self. There is no perception of a "self" within the five aggregates. Encountering conditions and objects, the mind does not give rise to the notion of "I." It does not oppose or feud with any person or matter, nor does it care about anything in its surroundings, because there is no "I" in the mind.

If one merely intellectually understands the Dharma or has a conceptual realization (解悟) of it, there is no samadhi whatsoever. There is no state of concentration, no perception of emptiness. The sense of "I" still remains in the mind; the "I-mind" is not dead. When encountering conditions and objects, one must rely on deliberate mental attention (manasikāra) from the sixth consciousness to recall that the five aggregates are without self. Once this conscious awareness is lost, the "I-mind" suddenly arises, and bodily, verbal, and mental actions lack restraint. Moreover, the illuminating function of the sixth consciousness is extremely limited, severely and obviously intermittent. It is always lost and cannot be maintained. Even if the power of the sixth consciousness is strong enough to maintain it for a period, it will inevitably be lost eventually, especially at the time of death.

All samadhis, whether primarily concentration-based or characterized by equipoise of concentration and wisdom, are the result of the accomplishment of the seventh consciousness (manas). Only when the seventh consciousness is stabilized, not scattered or chasing after objects, can a state of concentration arise. Only then can the seventh consciousness have sufficient energy to ponder the Dharma brought by the sixth consciousness, thereby comprehending the fundamental meaning and essential substance of the Dharma. Samadhi will inevitably manifest. This is what is called realization (證得).