Yamas gradually develop and nurture healthy social values. Yamas are also called Mahavratas or great vows and are not conditioned by birth, social status, caste, region (place of living) or times (occasion). Generally the observance of a social practice undergoes a change according to the then circumstances. For example in a society where the population of female out number that of males, there polygamy is allowed by law. However, the Yamas are not conditioned by any of the conditions above.
Ahimsa (non-violence) - Yama should be practised on both behavioural and mental levels. Injury may be of three kinds Krta or caused, Karita or caused through others and Anumodita or approved. Thus, not only actually causing injury to others should be avoided but also even thinking of violence or approving of injury should also be avoided. Greed or lobha, anger or krodha or misconceived motions of pleasure or moha can lead to these injuries. The intensity of the injury can be classified as mridu or mild, madhya or moderate and adhimatra or intense. Yoga demands ahimsa in totality; himsa (violence) does not mean only killing or hitting anyone, which is a limited meaning of the word in physical aspect. To hurt someone mentally is also a himsa, called the oral himsa. Yoga also states further that even thinking ill of someone is also a himsa, called the mental himsa. Hence, ahimsa covers all aspects such as physical, oral, mental. One, who observes ahimsa, surely succeeds in curtailing the feelings of enmity. If ahimsa is followed for a long time, not only the sadhaka, but his surroundings will also be affected and enmity shall be eradicated from the minds of all who come in contact with him. The adherence of ahimsa yama creates an atmosphere of friendliness and peace.
Satya (Truthfulness) - Yama indicates truthfulness, it also presupposes an honest and sincere act on the part of the sadhaka. An act of deceit or even an idea of deceiving is a breach of the Yama of satya. A sadhaka aspiring to realize "Ultimate Truth" must start with observing "Truthfulness" in his own life. Satya does not only cover speaking the truth. Proper understanding of the 'spoken' and the 'mind' is the truth. Here, the term 'proper' means exactly what is seen, understood or heard, the same thing should be followed by the tendency of the aspirant to talk and also think. When the sadhaka shall explain something to his listeners, he/she should be very clear in his conception and thoughts; if the conversation generates doubts or if it is not understood correctly by others, then that is not truth, even if it is true. God has created tongue for the benefit of all and not for destruction; thus the truth, which results in the destruction of someone or something, is also not the truth. Mahabharata has stated that silence is greater than the speech and true speech is greater than the silence.
Asteya (Non Stealing) - Yama means not depriving others of their belongings and also not keeping an intention or desire to possess things that belong to others. Thus it is "Mental Asteya". However, Asteya has a comprehensive meaning and means not keeping anything with self, which does not belong to the self. Picking up or possessing something, which does not have any owner, is also a theft. There is an increasing pressure on the mind after practicing theft. The mind is disturbed and there is no concentration in work. The pressure generated in the process does have bad effects on the body and the internal glands. If asteya is properly observed, the body and the mind do not have to undergo such strain.
Brahmacharya (Discipline in sex) - Yama denotes abstinence from sexual life. Generally Brahmacharya is translated as continence from sex, celibacy, chastity and so on. Thus, the broad meaning of Brahmacharya is a mode of behaviour which will be conducive for reaching the highest goal for the spiritual sadhaka. It is obvious that in such a disciplined life the proper restraint of sex activity is very important. Therefore, fundamentally sex is not a thing to be deprecated and to be prescribed. Here, forceful restraint on sexual urges is not indicated. A judicious control over sex is recommended, according to the needs of the sadhaka. In the human beings, the sexual instincts and its expressions have a very far-reaching influence on psychic, moral, mental and physical growth of the individual. Controlled enjoyment of desires and staying within the limit of dharma and science is included in the idea of continence. Desires, their fulfillment and enjoyment do have a place in the family life, but there should be some limit. Once the desires start ruling the mind of the sadhaka, he/she looses freedom. If the desires are not fulfilled, then the sadhaka eventually looses mental and physical well-being.
Aparigraha (Non Possessiveness) - Yama indicates the idea of leaving behind worldly pleasures or other forms of extravagant luxuries. Aparigraha means restraints from amassing or collecting the things. It also refers to give up the mental attachments to things. Aparigraha on mental level is 'samnyasa' and the practical aspect of 'samnyasa' in actual life is Aparigraha. Aparigraha without 'samnyasa' is not practical because the person may again aspire and try to acquire worldly things. Hence Aparigraha and 'samnyasa' should go hand in hand. One who learns and follows the path of aparigraha at its best, gains the knowledge of past, present and future. The Yogi also comes to know about his previous birth.
Some more components of Yama are Kshama, Dhruti, Daya, Arjav, and Mitahar. Kshama (forgiveness) is a big virtue. The mistakes of common people, which hurt or prove troublesome, should be pardoned by the sadhaka. Hence, the sadhaka should not resist or react against the improper attitude of another, since reaction is met with another reaction. Dhruti (courage) is essential for performing or achieving anything. A person actually has to fight with more of emotions than physical challenges in a lifetime. A sadhaka should have the courage to face the emotions and gain victory over them. Daya (Pity) is an action itself that means to assist someone with sympathy. To console someone by sympathising with kind words is oral daya; while thinking kindly in mind about the poor and wishing them all the best in life is mental daya. Daya not only leads to peace of the body as well as the mind, but also brings divine mental satisfaction. Aarjav (Humbleness) is a great virtue to be followed by the sadhaka. Casting aside of one's ego is important in the regular routing. When there is no ego, there are no problems and one does not have to search for the solutions. When the ego is forsaken, the heart, and mind turn soft and simple that helps the sadhaka to go nearer to the God. The virtue of Mitahar (Restricted diet) says that the sadhaka should have the capability to avoid excess consumption of food. One should take the necessary meal at proper times of the day.
The concept of Yama and Niyama are held at high regards in the science of Yoga. Patanajali has stated in this work that a person neglecting the practice of Yama shall not be able to attain salvation. Niyam are the first two aspects of the eightfold Ashtanga Yoga. In many contexts, it has been observed that Yama and Niyama are called restrictions, but they actually are freedom from restrictions. Yoga essentially starts with freedom from such restrictions.
The concept of Yama is the basic foundation stone of the Yoga concept at large. The science of Yoga itself stresses on renunciation. However, even if the sadhaka resides within the society, he/she should follow the path of Yama. 'Yama' comprehensively directs about how a common man should behave in the society, whereas 'Niyama' guide the mass regarding their individual behaviour.