The (), and their complement, the niyamas, represent a series of "right living" or ethical rules within Yoga philosophy. The word means "reining in" or "control".
The earliest mention of is in the Rigveda. More than fifty texts of Hinduism, from its various traditions, discuss .
The apply broadly and include self-restraints in one's actions, words, and thoughts.
Etymology and meaning
The earliest mention of is found in the Hindu scripture Rigveda, such as in verse 5.61.2, and later in the Jain Agamas. The word in the Rigveda means a "rein, curb", the act of checking or curbing, restraining such as by a charioteer or a driver. The were explained in detail by Patañjali in the Yoga Sūtras of Patanjali as the first step of the eight-fold path of yogic philosophy and practice for attaining enlightenment and union of the mind, body and soul.
Yamas by source
The number of Yamas varies with the source:
{| class="wikitable"
|-
! No. !! 5 Yamas<br/>Yogasūtra 2.30<br/>cf. Ethics of Jainism !! 10 Yamas<br/>Śāṇḍilya Upanishad,<br/>Svātmārāma
|-
| 1
| colspan="2" | Ahiṃsā (अहिंसा): Non-violence (literally "Non-harming")
|-
| 2
| colspan="2" | Satya (सत्य): Truthfulness (Not lying); speech that is non-deceptive, non-distorted, and purposeful
|-
| 3
| colspan="2" | Asteya (अस्तेय): Not stealing
|-
| 4
| colspan="2" | Brahmacharya (ब्रह्मचर्य): Chastity, sexual restraint, focus (not distracted)
|-
| 5
| colspan="2" | Aparigraha (अपरिग्रहः): Non-avarice, non-possessiveness
|-
| 6 || — || Kṣamā (क्षमा): Patience, forgiveness.
|-
| 7 || — || Dhrti (धृति): Fortitude, perseverance with the aim to reach the goal
|-
| 8 || — || Dayā (दया): Compassion
|-
| 10 || — || Mitāhāra (मिताहार): Measured diet
|}
At least sixty ancient and medieval era Indian texts are known that discuss . Most are in Sanskrit, but some are in regional Indian languages. Of the sixty, the lists in eleven of these texts are similar, but not the same, as that of Patanjali's. In verse 31.21, Ahirbudhnya Samhita includes as the virtue of forgiveness and restraint from continued agitation from wrong others have done. lists many of the ten above, but explains why it is a virtue in a different way. For example, the text explains is an ethical precept and the restraint from too much and too little emotions. It suggests reflects one's inner state, is the expression of kindness towards kin, friend, stranger, and even a hostile person, and that one must remain good and kind no matter what the circumstances. This view of is shared in Shandilya Upanishad and Jabala Darshana Upanishad. Atri Samhita in verse 48, lists () as the restraint from cruelty to any living being by one's actions, words or in thoughts. Shivayoga Dipika in verse 2.9 substitutes for , defining as "sweet and true speech".