The catalyst for the Buddha's enlightenment was his penetrative and perfect insight into the dependently arisen nature of all that exists. Dependent Origination (engi 縁起) is how all things are born, exist, and die - all without an undying “self” or “soul.” All things are conditioned by other things. everything is subject to change. Nothing is permanent; nothing has a self-subsisting nature. Neither the self nor anything else in the universe exists immutably, independently, or permanently.

All things that come into being - whether it be human life, a thought, or a galaxy - depend on an endless chain of preceding causes and conditions. All things arise, evolve, and eventually dissipate, because of complex causal conditions. This law is linked with the Second and Third Truths of the Four Truths of The Noble One.

The Second Truth states that - There is a cause or origin of dissatisfaction and suffering (Jittai 集諦). This can be stated as; Because of this, there is that.

The Third Truth states that - There is an end to dissatisfaction and suffering (Mettai 滅諦). This can be stated as; Without this, that can’t be.

Remove the causes and conditions of a given thing, and that thing cannot be. Remove the causes and conditions of suffering, and suffering ceases.

The Buddha realised that all phenomena are dependently arisen. Everything that exists is a nexus of causal factors. Thus, all phenomena are impermanent; they arise at some point in time and cease to be at another point in time.

All things in existence are endowed with three characteristics, called the Three Marks of The Dharma (sanbõin 三法印):

1) All things are impermanent. (shogyõ mujõ 諸行無常)
2) All things are selfless, unsubstantial (shohõ muga 諸法無我)
3) Nirvana is tranquility, righteousness (nehan jakujõ 涅槃寂静)

"The enlightened mind is a mind that is always contemplating impermanence.
The practitioner of Buddhism must humbly contemplate the Buddha's words, 'All things are impermanent.'
Time never stops, the hours do not wait. We must indeed be aware that death may come at any moment."
- Suzuki Shõsan Rõshi

Enlightenment, Buddha-awareness, is the awareness of impermanence. Life is uncertain, death is certain. Knowing that death is certain and is the natural phenomenon that everyone has to face, we should not be afraid of death. To be considered free in life, we must be free from the fear of death. One who practices the way of the Buddha must humbly contemplate the words "All things are impermanent." We must indeed be aware that birth and death come at any moment. Every moment is impermanent. Enlightenment is to be achieved by the awareness of impermanence.

The religious teaching of Buddhism is based upon the teaching of impermanence (mujõ 無常). All things arise, go through a series of changes and die. All phenomenon are impermanent, every living thing eventually dies. Life has a limit and is always in a state of uncertainty. This is an undeniable reality.

"Make the character 死 (death) master in your heart, observing it and letting go of everything else."
- Suzuki Shõsan Rõshi

Many people may think that pursuing material happiness or riches is most important in life. But next to the reality of death these things pale. When you are faced with death, what good is being wealthy?

Even within our own bodies there are cells that are dying each moment, and at the same time they are being replaced by new cells.

"Everything in the world arises, changes and perishes; nothing remains constant for even a single moment."
- The Buddha

Insight into dependent origination illuminates specifically the processes whereby suffering arises and ceases in a person.

It was the Buddha's application of his perfect insight to his own situation that led to his attainment of enlightenment, bodhi (bodai 菩提). An enlightened person, having achieved bodhi (bodai 菩提) is one who is fully liberated by the destruction of the defilements and perfect insight into the dependently arisen nature of all things. In short such a person lives having achieved nirvana (nehan 涅槃).

Lingering attachments drain our energy if we don't make efforts to guard against them. The true way to practice is to keep up our energy and intention. We can do this in any number of ways; reciting the nembutsu, sitting in meditation, practising budõ or some other exercise, cultivating the earth, selling one's goods, so long as these acts are performed with a mind aware of the impermanence of all things. This intense awareness adds life to our practice and cuts away our delusions.