The wise ones teach that withdrawing the senses from their objects is known as pratyāhāra, a turning inward that quiets the mind’s restless wanderings. When the mind is then bound and held steady at a single point or place, that is called dhāraṇā. If this steadiness is maintained, a deeper state arises: meditation, or dhyāna, where the mind becomes one-pointed and free from all distracting impressions. When, in this meditation, only pure awareness remains—so that even the sense of the body seems absent—this is samādhi, the highest absorption. But know that the root of all these stages is prāṇāyāma, the discipline of the vital breath. Prāṇa, the vital wind within the body, is to be restrained—this is called yama. The twice-born sages describe three grades of restraint: mild, moderate, and superior. The regulation of prāṇa and apāna, the upward and downward breaths, is prāṇāyāma, measured in units called mātrās. The lowest measure is twelve mātrās, the highest is also twelve, and the middle measure is twenty-four. The principal or superior practice is thirty-six mātrās, which brings about sweat, trembling, and a sense of rising, each in order. In the pursuit of yogic bliss, as well as sleep and dizziness, various signs may appear: horripilation, inner sounds, heightened awareness, bodily shaking, and trembling. When dizziness and faintness from sweat arise, this is considered the highest and best prāṇāyāma. Prāṇāyāma may be practiced with or without a seed (mantra), with or without recitation, and the breath itself may be as difficult to control as an elephant, a deer, or a lion. But when the wind is disciplined and restrained, it behaves as it should—if it remains unsteady, even yogis struggle to master it. With proper practice, however, even the wildest breath becomes calm, just as an untamed animal can be brought to steadiness. Through the force of time and repeated effort, the breath is gradually mastered. Familiarity brings steadiness and evenness. The yogi who practices in this way does not suffer affliction; prāṇa is purified by this discipline. Prāṇāyāma, when performed with wisdom and unity, protects the practitioner from faults of mind, speech, and body, and safeguards the body itself. Therefore, as faults are destroyed and exhalation is diminished, prāṇāyāma gradually brings about divine peace and other noble qualities: peace, supreme tranquility, radiance, and clarity, each attained in turn. Of these, peace is always declared first. Peace is the removal of all innate and incidental sins; supreme tranquility is complete restraint, as taught in the tradition. Light is the radiance that shines everywhere, and clarity is the brilliance of the senses, the intellect, and even the winds within. This clarity, called prasāda, manifests in the body as the five principal winds: prāṇa, apāna, samāna, udāna, and vyāna. There are also five subsidiary winds: Nāga, which causes belching; Kūrma, which opens the eyes; Kṛkala, which stirs hunger; Devadatta, which brings yawning; and Dhanaṃjaya, which produces sound and pervades even after death. Prāṇa is the wind that causes movement; apāna expels food and other wastes. Vyāna pervades the limbs and agitates diseases, and udāna stirs the vital points. Samāna brings balance to the limbs. Thus, the ten winds are named, each with its own function. The clarity of these ten winds is achieved through breath-control. There are also ten designations of the intellect: Viśva, Mahān, Prajñā, Manas, Brahmā, Citi, Smṛti, Khyāti, Saṃvit, Īśvara, and Mati. These are the names of the intellect, the great principles, and their clarity is also attained through breath-control. Viśva is the state of universality, the eldest of all principles; Mahān is the greatest in measure. Brahmā is the vastness and source of knowledge, the cave from which the mind thinks. Citi gathers all actions for the sake of enjoyment; Smṛti is memory, Saṃvit is that by which all is known. Khyāti reveals knowledge in many ways; Īśvara is the Lord of all principles, the knower of everything. Mati is the faculty of thought and consideration, and buddhi is what enables understanding. The clarity of intellect is accomplished by breath-control; by this practice, all faults are restrained—this is yama. Sin is destroyed through dhāraṇā and pratyāhāra, when one regards the objects of the senses as poison and meditates on qualities that are not lordly. By samādhi, the best of ascetics increase wisdom. Having attained the proper state, one should practice the eight limbs of yoga in order. When the seats for yoga are properly obtained, the knower of the self does not experience visions of yoga at inappropriate times. One should not practice yoga in places of fire, water, heaps of dry leaves, places infested with creatures, cremation grounds, ruined cowsheds, crossroads, noisy or fearful places, heaps of ant-hills, impure places, or where wicked people or swarms of insects abound. Nor should one practice where there is bodily distress or mental disturbance. Instead, one should choose a well-concealed, auspicious, and pleasant place—such as a cave in a mountain—for the practice of yoga.