Patanjali’s eight limbs of yoga
Many people first encounter yoga through physical postures. In Patanjali’s Yoga Sutras, posture comes third in a sequence of eight limbs. B. K. S. Iyengar reads the sequence as an integrated practice in which conduct, body, and attention all matter.
Conduct and posture
Yama describes restraints that guide how we act. Niyama describes observances we cultivate in our own lives. Nonviolence is a yama and contentment is a niyama. Asana introduces posture. Iyengar asks how effort is distributed and what parts of the body go unnoticed when we concentrate on outward form.
Breath and the senses
Pranayama concerns the deliberate regulation of breathing. Pratyahara describes a change in the relationship between attention and sensory impressions. These two limbs help explain the transition from working with the body and breath to directing attention.
Three inward limbs
Dharana is holding attention on a chosen area or object. Dhyana is the continuity of attention to that same object. In samadhi, the object becomes central to the experience. The third chapter of the sutras calls the three together, when applied to the same object, samyama.
How Iyengar groups the eight limbs
Iyengar sees three kinds of work within the sequence. Yama and niyama guide the art of living. Asana, pranayama, and pratyahara are an outward inquiry into how the body, breath, senses, and attention work together. Dharana, dhyana, and samadhi form an inward inquiry. His grouping explains why pratyahara belongs at a turning point. It completes a phase in which sensory experience is a direct part of practice, and prepares for a phase concerned with sustained attention.
A single posture from several angles
Picture someone sitting down to practice at the end of a long day. They choose a position that feels steady and make an adjustment when a knee feels strained. The choice brings the concern for nonviolence into the work of asana. Once seated, they notice whether the position leaves room to breathe comfortably. When a sound draws their attention, they can observe the impulse to turn toward it. One ordinary situation raises questions associated with several limbs, even if the person is simply sitting and noticing.
Reading the sequence as a whole
The order shows how one kind of work can prepare for another. A position that takes constant adjustment can make it difficult to attend to the breath. The effort of choosing an object of attention becomes easier to see once you recognize how often a sensation or a thought redirects you. Read this way, the list gives you a way to understand what a particular practice is asking of you and why earlier limbs still matter.
Using the map
As you read further, notice the question each limb addresses. One might concern a decision in daily life, another the way you sit, and another what happens after you choose where to direct attention.
Source
B. K. S. Iyengar. Heart of the Yoga Sutras.