[Among the three essentials – Ethical Conduct (Sila), Mental Discipline (Samādhi) and Wisdom (Paññā)] Mental Discipline includes three other factors of the Eightfold Path: Right Effort, Right Mindfulness (or Attentiveness) and Right Concentration. (Nos. 6, 7 and 8 in the list).

Right Effort is the energetic will (1) to prevent evil and unwholesome states of mind from arising, and (2) to get rid of such evil and unwholesome states that have already arisen within a man, and also (3) to produce, to cause to arise, good and wholesome states of mind not yet arisen, and (4) to develop and bring to perfection the good and wholesome states of mind already
present in a man.

Right Mindfulness (or Attentiveness) is to be diligently aware, mindful and attentive with regard to (1) the activities of the body (kāya), (2) sensations or feelings (vedanā), (3) the activities of the mind (citta) and (4) ideas, thoughts, conceptions and things (dhamma). …

The third and last factor of Mental Discipline is Right Concentration leading to the four stages of Dhyāna, generally called trance or recueillement. In the first stage of Dhyāna, passionate desires and certain unwholesome thoughts like sensuous lust, ill-will, languor, worry, restlessness, and skeptical doubt are discarded, and feelings of joy and happiness are maintained, along with certain mental activities. In the second stage, all intellectual activities are suppressed, tranquility and ‘one-pointedness’ of mind developed, and the feelings of joy and happiness are still retained. In the third stage, the feeling of joy, which is an active sensation, also disappears, while the disposition of happiness still remains in addition to mindful equanimity. In the fourth stage of Dhyāna, all sensations, even of happiness and unhappiness, of joy and sorrow, disappear, only pure equanimity and awareness remaining.

Thus the mind is trained and disciplined and developed through Right Effort, Right Mindfulness, and Right Concentration.

[Among the three essentials – Ethical Conduct (Sila), Mental Discipline (Samādhi) and Wisdom (Paññā)] Ethical Conduct (Sīla), based on love and compassion, includes three factors of the Noble Eightfold Path: namely, Right Speech, Right Action and Right Livelihood. (Nos. 3, 4 and 5 in the list).

Right speech means abstention (1) from telling lies, (2) from backbiting and slander and talk that may bring about hatred, enmity, disunity and disharmony among individuals or groups of people, (3) from harsh, rude, impolite, malicious and abusive language, and (4) from idle, useless and foolish babble and gossip. When one abstains from these forms of wrong and harmful speech one naturally has to speak the truth, has to use words that are friendly and benevolent, pleasant and gentle, meaningful and useful. One should not speak carelessly: speech should be at the right time and place. If one cannot say something useful, one should keep ‘noble silence.’

Right Action aims at promoting moral, honorable and peaceful conduct. It admonishes us that we should abstain from destroying life, from stealing, from dishonest dealings, from illegitimate sexual intercourse, and that we should also help others to lead a peaceful and honorable life in the right way.

Right Livelihood means that one should abstain from making one’s living through a profession that brings harm to others, such as trading in arms and lethal weapons, intoxicating drinks, poisons, killing animals, cheating, etc., and should live by a profession which is honorable, blameless and innocent of harm to others. One can clearly see here that Buddhism is strongly opposed to any kind of war, when it lays down that trade in arms and lethal weapons is an evil and unjust means of livelihood.

These three factors (Right Speech, Right Action and Right Livelihood) of the Eightfold Path constitute Ethical Conduct. It should be realized that the Buddhist ethical and moral conduct aims at promoting a happy and harmonious life both for the individual and for society. This moral conduct is considered as the indispensable foundation for all higher spiritual attainments. No spiritual development is possible without this moral basis.

These eight factors [of the Noble Eightfold path] aim at promoting and perfecting the three essentials of Buddhist training and discipline: (a) Ethical Conduct (Sila), (b) Mental Discipline (Samādhi) and (c) Wisdom (Paññā). It will therefore be more helpful for a coherent and better understanding of the eight divisions of the Path, if we group them and explain them according to these three heads.

Ethical Conduct (Sīla) is built on the vast conception of universal love and compassion for all living beings, on which the Buddha’s teaching is based. It is regrettable that many scholars forget this great ideal of the Buddha’s teaching, and indulge in only dry philosophical and metaphysical divagations when they talk and write about Buddhism. The Buddha gave his teaching ‘for the good of the many, for the happiness of the many, out of compassion for the world’ (bahujanahitāya bahujanasukhāya lokānukampāya).