Ignorance is the fundamental cause of our non-enlightenment.
"Ignorance is merely a false mark. It is not real, and so it is subject to production, extinction, increase, decrease, defilement, purity, and so on. Ignorance is empty and unreal. It has no real substance. It is only a name and corresponds to nothing in reality. It cannot be grasped or seen. It causes us to undergo birth, old age, sickness, and death, worry,grief, and misery." (DFS II 374)
Ignorance is the first link in the Twelvefold Dependent Arising.
1) Ch. wu ming , 2) Skt. avidya, 3) Pali avijja, 4) Alternate Translations: lack of knowledge, nescience.
See also: Twelvefold Dependent Arising, attachment.
BTTS References: DFS III 374.
This day is already done.
Our lives are that much less.
We're like fish in a shrinking pond;
What joy is there in this?
We should be diligent and vigorous,
As if our own heads were at stake.
Only be mindful of impermanence,
And be careful not to be lax.
(Universal Worthy Bodhisattva's Verse of Exhortation, TT 111)
The Buddha taught about impermanence in order to help living beings sever their attachment to the ideas of permanence and the eternal, particularly those taught by non-Buddhist religions.
The Buddha said to the great king [Prasenajit], 'Now I will question you. Is your present physical body like vajra, undecaying and immortal? Or does it deteriorate?'
'World-Honored One, this body of mine will keep changing until eventually it has completely disintegrated.'
The Buddha said, 'Great King, you have not yet perished. How do you know that you will perish?'
'World-Honored One, although my impermanent, deteriorating body has not yet totally disintegrated, I observe now, in thought after thought, that it fades away; renewing itself yet failing to remain and gradually burning away, as if fire were turning to ashes. This perishing without cease convinces me that this body will eventually completely disintegrate.'
The Buddha said, 'So it is. Great King, at your present age you are already old and declining. How does your appearance compare to when you were a youth?'
'World-Honored One, in the past, when I was a child, my skin was moist and shining. When I reached the prime of life, my blood and breath were full. But now in my elderly years, as old age presses upon me, my frame and shape are withered and worn out. My vitality is dull and unclear. My hair is white and my face is wrinkled. I haven't much time remaining. How can this be comparable to the way I was in the prime of life.?'
'The Buddha said, 'Great King, your appearance cannot have deteriorated suddenly.'
The king said, 'World-Honored One, the change has been a hidden transformation of which I honestly have not been aware. I have come to this gradually through the passing of winters and summers. Why? In my twenties, though I was still young, my appearance had aged compared with my first ten years. My thirties were a further decline from my twenties, and now, at two years past sixty, I look back on myself in my fifties as being strong and healthy. World-Honored One, I am looking at these hidden transformations. Although the changes wrought by this descent into death are evident through the decades, I might consider them further in finer detail. These changes do not occur simply between one period of life and another; there are actually changes year by year. And how can there be only yearly changes? There are also monthly transformations. How can there just be monthly transformations? There are further alterations day by day. As I ponder them deeply and examine them closely, I find that kshana after kshana, thought after thought, they never stop. And so I know my body will keep changing until it completely disintegrates. . . .'
The Buddha said, '. . . what changes will perish. What does not change is fundamentally free of production and destruction. How can it be subject to your birth and death? Yet you still bring up what Maskari Goshaliputra and the others all say: that after the death of the body there is total annihilation.'
The king heard those words, believed them, and knew that when the life of the body is finished, one is destined for rebirth. . . ." (SS II 25-35 BTTS rev. ms.)
Whatever flourishes must have decay.
Every union entails separation
The prime of one's life does not last long.
Health is encroached upon by illness.
Life is swallowed up by death.
There are no dharmas that last forever.
Kings attain to sovereignty,
With power that has no equal.
Yet all of it declines and perishes,
And our lives are that way too.
The wheel of sufferings has no bounds.
It keeps turning without cease.
All three realms are impermanent,
And none of the existences is bliss.
(NS Ch2 #25 BTTS, draft tr.)
Impermanence together with suffering and no-self are called the Three Characteristics of the Conditioned World. In the third of the Four Applications of Mindfulness the impermanent nature of the mind is contemplated.
1) Ch. wu chang , 2) Skt. anitya, 3) Pali anicca, 4) Alternate Translations.
See also: suffering, no-self, Four Applications of Mindfulness.
BTTS References: TT 110, 111 (2 verses); SS II 24-36 (text only); Nirvana Sutra Ch. 2 Pt. 1 24-25 and lectures.