Within Tendai Buddhism, the Four Samādhis (shishu zanmai) present a comprehensive vision of meditative life that embraces both formal practice and everyday activity. They are traditionally named according to bodily posture, yet each points beyond mere physical form to a particular mode of concentrated awareness. Taken together, they trace a movement from structured, intensive retreat practice toward an integration of samādhi with the full range of human conduct.

The first is the Constantly Sitting Samādhi (jōza zanmai), an extended period of seated meditation, often maintained for many days or even a full ninety-day retreat. Practitioners remain seated without lying down, directing their attention to contemplation and insight. This practice is associated with deep concentration and the investigation of the nature of phenomena, including their emptiness and the Middle Way that transcends extremes. It represents a radical stilling of bodily movement so that the mind can become thoroughly settled and clear.

The second is the Constantly Walking Samādhi (jōgyō zanmai), in which practitioners engage in continuous walking meditation, typically circumambulating a Buddha image. This is often accompanied by recitation of the Buddha’s name, especially that of Amitābha, and sustained visualization or recollection of the Buddha. The body is in motion, yet the mind is gathered into a single, unwavering focus. Here, devotion, movement, and concentration are woven together into one continuous act of practice.

The third, the Half-Walking, Half-Sitting Samādhi (hangyō hanza zanmai), alternates periods of walking and sitting meditation. This form allows for a dynamic balance between stillness and movement, and it can incorporate practices such as sutra recitation and repentance rituals. By shifting rhythmically between postures, it harmonizes calm and insight in a way that is both rigorous and adaptable. It serves as a bridge between the intensity of single-mode retreats and the more fluid practice of daily life.

The fourth is the Neither-Walking-Nor-Sitting Samādhi (higyō hiza zanmai), which extends meditative awareness into all activities that do not fit neatly into formal walking or sitting practice. This includes standing, speaking, working, studying scriptures, and engaging in ordinary tasks, all undertaken with continuous mindfulness and contemplation of the teachings. In this mode, samādhi is no longer confined to special times or postures, but is cultivated amid the full range of human experience. The Four Samādhis thus sketch a path in which concentrated awareness gradually permeates every aspect of life, so that practice and daily conduct are no longer two separate realms.