The Distinction Between Samādhi and Passaddhi

Concentration encompasses tranquility, which is the initial stage of concentration and its most basic manifestation. First, the body becomes still and motionless; then, mental thoughts gradually settle and grow quiet. As the practice progresses, concentration deepens. It is no longer merely the stillness of body and mind—some phenomena begin to vanish, the mind becomes more focused and unified, and eventually, even mental thoughts disappear entirely. From the second dhyāna (meditative absorption) onwards, the five sensory consciousnesses cease to function. From the fourth dhyāna onwards, breathing, pulse, and heartbeat stop functioning. The deeper the concentration, the fewer phenomena manifest. The abundance or scarcity of phenomena is determined by the mental faculty. The depth of concentration lies in whether the mental faculty is subdued, and in how many phenomena the mental faculty clings to.