Just four weeks after his Enlightenment , seated under a banyan tree, the Buddha thought to himself in deep compassion and wholesome wisdom:
'I have realized this Truth which is deep, difficult to see, difficult to understand... comprehensible only by wise...Men who are overpowered by passion and surrounded by a mass of darkness cannot see this Truth.' He hesitated a moment whether it would not be in vain to explain to the world the Truth he had just realized. However, he finally decided to teach it.
Then next thought arose: 'Where to start.'
Why did he start from the Four Noble Truth(四聖諦)? Because he knew and saw that all sufferings of the 'Being' came from the ignorance(無明) and attachment(着).
'As you all like to follow logics based on your analogy,' he thought, 'I will show you how the Buddha would discourse the Truth in your way.'
The first paragraph is in the record. This last one I just imagined.
The First Noble Truth: Dukkha
Chinese translation of this word (苦) is 'pain','suffering'... The Buddha used this word to include all the nature of life, its suffering, its sorrow and joy, its imperfection and unsatisfactoriness, its impermanence and insubstantiality.
The Buddha said 'O bhikkhus, what is dukkha? It should be said that it is the Five Aggregates of Attachment(Five Skandhas 五蘊).' We call them as combination a 'being' or an 'individual', or 'I', only a convenient name or label. So we must understand the fact that all 'being' including ourselves and the Cosmos is impermanent, and continuously changing therefore it is 'suffering'.
The Second Noble Truth: Samudaya "The Arising of Dukkha"
Where the dukkha is originated? It comes from the 'Thirst' which produces re-existence and re-becoming, and which finds fresh delight now here and now there, namely, (1) thirst for sense-pleasures, (2) thirst for existence and becoming and (3) thirst for non-existence (self-annihilation). It has its center the false idea of self arising out of ignorance. Philosophically it is also called as 'Volition' whose action is 'karma'(業) and exists within dukkha itself causing, germing, and destructing the dukkha itself.
'When the Aggregate arises, decay and die, O bhikkhu, every moment you are born, decay and die.' The Buddha said. Understanding of this 'Samudaya' is required to discard, to eliminate, and eradicate it in the course of realization of 'Nirvana'.
The Third Noble Truth: Nirodha "The Cessation of Dukkha"
As long as the 'thirst' to be and to become exists 'samsara'( the cycle of continuity ) goes on. It can stop and thereby the suffering stop only when the driving force 'thirst', the main root of dukkha, is cut off through wisdom(prajnaparamita) which sees Reality, Truth, Nirvana.
The foregoing understanding and identification of the Noble Truth 'dukkha' and its origin were all made for this Third Noble Truth 'nirodha', the Cessation of 'dukkha' i.e. Nirvana, the Absolute Truth. When wisdom is developed and cultivated according to the Fourth Noble Truth(四聖諦), it sees the secret of life, the reality of things as they are. When the secret is discovered, when the Truth is seen, all the forces which produce the continuity of samsara in illusion become calm and incapable of producing any more karma-formations.
'O bhikkhus, what is the Absolute? It is the extinction of desire, the extinction of hatred, the extinction of illusion.'
'This, his deliverance, founded on Truth, is unshakable. O bhikkhu, that which is unreality is false; that which is reality, Nirvana, is Truth. Therefore, O bhikkhu, a person so endowed with this Absolute Truth. For, the Absolute Noble Truth is Nirvana, which is Reality.'
The Fourth Noble Truth: Megga "The Path"
Here, the Buddha is trying to teach you the Middle Path he discovered through his personal experience which gives vision and knowledge, which leads to Calm, Insight, Enlightment, Nirvana. His 45 yeas of teaching was wholly devoted to it. He explained it in different words to different people, according to the stage of their development and their capacity. This Middle Path(中道) is generally referred to as the Noble Eightfold Path(八正道): namely,
Right Thought .....Constitute Wisdom
Right Livelihood .....Ethical Conduct
Right Concentration.....Mental Discipline
According to Buddhism for a man to be perfect, there are two qualities that he should develop equally: compassion in one side, and wisdom on the other. The Path leads to the realization of the Ultimate Reality, to complete freedom, happiness and peace through moral, spiritual, and intellectual perfection, Nirvana(涅槃).