"YAMA is the first limb of Raja yoga (a.k.a. Ashtanga or classical yoga). It is a Sanskrit word that means "death." It is a set of social disciplines to be maintained by a yoga practitioner which includes non-violence", "absence of falsehood", "non-stealing", "sexual continence", and "absence of avarice". Other branches of yoga actually have more than just five abstentions, but I don't want to be greedy, really, so let me show the "absence of avarice" right now by being satisfied with what I have.
You may be asking why the Hindus would use such a word as "death" to name the first set of practices in yoga. Well, according to Indian mythology, Yama is the god of death (the lord of the celestial abodes that one visits after one's life has ended). Other cultures have their own version of Yama, like Anubis (Egyptian mythology), Hades (Greek mythology), and Pluto (Roman mythology). However, in the consideration of yoga, what is being represented is not the death of the physical body, but instead, the death of one's identification with individual existence, which is referred to in psychology as the 'ego'.
WHY DO WE NEED TO PRACTICE YAMA?
All spiritual and religious traditions have guiding principles for engaging with others in society. These principles encourage ethical ways of living, but I do believe it goes far beyond that. If you contemplate on the concept about bringing death to the ego, you may also arrive with the following ideas:
* You live in a world inhabited by other beings who, just like you, need to evolve spiritually in their own unique way. Earth is our training ground and we need to give each other the chance to learn by making sure that this place we call reality is conducive for this goal. Wouldn't it be fun to live in a world without violence, dishonesty, theft, sexual misconduct, and greed - all crazy impulses that the helpless ego cannot control?
* The Ego is the organizing center of the mind. Most of the time, however, it doesn't do a good job in controlling your thoughts, especially when it is disturbed because of one's ignorance of moral values. This is why there is a need for you to establish a connection with your true self by doing yoga so that you can abandon your conceptions of being in control.
* The Ego creates a sense of attachment between consciousness and the physical body. In the advanced practices of yoga, practitioners are required to work with the subtle and causal bodies, so there's really a need to let go of one's ego. This stage is said to be wherein one may experience going out of one's body and even out of the the realm of mind. It's totally different from being insane, of course.
THE YAMAS (5 ABSTENTIONS)
1. AHIMSA (NON-VIOLENCE)
The first Yama called himsa means "violence." Ahimsa is the practice of non-violence (physical, mental, and emotional) towards other living beings and yourself. To the Hindus, violence or himsa can be of three types: krta (harming others directly), karita (harming others indirectly) and anumodita (supporting an act of violence).
2. SATYA (ABSENCE OF FALSEHOOD)
The second Yama called satya means "truthfulness or the absence of falsehood." Satya is the practice of speaking the truth at all times. People who faithfully practice the four other abstentions have no problem in telling the truth in everything they say. The ones who, for example, beat people up, fornicate, steal from others, and so on will undoubtedly have a hard time dealing with their conscience.
3. ASTEYA (NON-STEALING)
The third Yama called steya means "theft." Asteya is the practice of not stealing. Obviously, there is an increasing pressure on your mind when you take something which is not yours and keep it to yourself. Violate this code and you also violate three others: ahimsa, satya, and aparigraha.
4. BRAHMACHARYA (SEXUAL CONTINENCE)
The fourth Yama called brahmacharya is derived from the words brahman meaning "unity consciousness" and achara meaning "pathway." Bramacharya may have two meanings. In one sense, it means avoiding over-indulgence of the senses. Another meaning refers to abstinence particularly in terms of sexual activity.
5. APARIGRAHA (ABSENCE OF AVARICE)
The fifth Yama called aparigraha means "not being acquisitive." It is the avoidance of unnecessary attainment of things that are not essential to maintaining life. The logic behind this is pretty simple, really. Acquiring fame and fortune, for example, guarantees attachment to them. As your fame and fortune increases, so does your fear of losing them. On a different note, it is said that if you faithfully observe aparigraha, you may attain knowledge of past, present and future and also knowledge of your previous births.