Upadana

Upādāna is the Sanskrit and Pāli word for "clinging," "attachment" or "grasping", although the literal meaning is "fuel." Upādāna and taṇhā are seen as the two primary causes of suffering. The cessation of clinging leads to Nirvana Types of clinging In the Sutta Pitaka, the Buddha states that there are four types of clinging:

• sense-pleasure clinging (kamupadana)
• wrong-view clinging (ditthupadana)
• rites-and-rituals clinging (silabbatupadana)
• self-doctrine clinging (attavadupadana).

The Buddha once stated that, while other sects might provide an appropriate analysis of the first three types of clinging, he alone fully elucidated clinging to the "self" and its resultant suffering.
The Abhidhamma and its commentaries provide the following definitions for these four clinging types:

1. sense-pleasure clinging: repeated craving of worldly things.
2. wrong-view clinging: such as emotional contation or nihilism.
3. rites-and-rituals clinging: believing that rites alone could directly lead to liberation, typified in the texts by the rites and rituals of "ox practice" and "dog practice."
4. self-doctrine clinging: self-identification with self-less entities (e.g., illustrated by MN 44, and further discussed in the skandha and anatta articles).

According to Buddhaghosa, the above ordering of the four types of clinging is in terms of decreasing grossness, that is, from the most obvious (grossest) type of clinging (sense-pleasure clinging) to the subtlest (self-doctrine clinging).

Interdependence of clinging types

self-doctrine clinging
↓
wrong-view clinging
↓		↓
rites-and-rituals clinging		sense-pleasure clinging

Buddhaghosa further identifies that these four clinging types are causally interconnected as follows:

1. self-doctrine clinging: first, one assumes that one has a permanent "self."
2. wrong-view clinging: then, one assumes that one is either somehow eternal or to be annihilated after this life.
3. resultant behavioral manifestations:
   1. rites-and-rituals clinging: if one assumes that one is eternal, then one clings to rituals to achieve self-purification.
   2. sense-pleasure clinging: if one assumes that one will completely disappear after this life, then one disregards the next world and clings to sense desires.

This hierarchy of clinging types is represented diagrammatically to the right.
Thus, based on Buddhaghosa's analysis, clinging is more fundamentally an erroneous core belief (self-doctrine clinging) than a habitualized affective experience (sense-pleasure clinging).

Manifestations of clinging

In terms of consciously knowable mental experiences, the Abhidhamma identifies sense-pleasure clinging with the mental factor of "greed" (lobha) and the other three types of clinging (self-doctrine, wrong-view and rites-and-rituals clinging) with the mental factor of "wrong view" (ditthi). Thus, experientially, clinging can be known through the Abhidhamma's fourfold definitions of these mental factors as indicated in the following table:

	characteristic	function	manifestation	proximate cause
greed (lobha)	grasping an object	sticks, like hot-pan meat	not giving up	enjoying things of bondage
wrong view (ditthi)	unwise interpreting	presumes	wrong belief	not hearing the Dhamma

To distinguish craving from clinging, Buddhaghosa uses the following metaphor:

"Craving is the aspiring to an object that one has not yet reached, like a thief's stretching out his hand in the dark; clinging is the grasping of an object that one has reached, like the thief's grasping his objective.... [T]hey are the roots of the suffering due to seeking and guarding."

Thus, for instance, when the Buddha talks about the "aggregates of clinging," he is referring to our grasping and guarding physical, mental and conscious experiences that we falsely believe we are or possess.

As part of the causal chain of suffering

In the Four Noble Truths, the First Noble Truth identifies clinging (upādāna, in terms of "the aggregates of clinging") as one of the core experiences of suffering. The Second Noble Truth identifies craving (tanha) as the basis for suffering. In this manner a causal relationship between craving and clinging is found in the Buddha's most fundamental teaching.
In the twelve-linked chain of Dependent Origination (Pratītyasamutpāda, also see Twelve Nidanas), clinging (upādāna) is the ninth causal link:

• Upādāna (Clinging) is dependent on Tṛṣṇā (Craving) as a condition before it can exist.

"With Craving as condition, Clinging arises".

• Upādāna (Clinging) is also the prevailing condition for the next condition in the chain, Becoming (Bhava).

"With Clinging as condition, Becoming arises."

According to Buddhaghosa, it is sense-pleasure clinging that arises from craving and that conditions becoming.

Upādāna as fuel

Professor Richard F. Gombrich has pointed out in several publications, and in his recent Numata Visiting Professor Lectures at the University of London, School of Oriental and African Studies (SOAS), that the literal meaning of upādāna is "fuel". He uses this to link the term to the Buddha's use of fire as a metaphor. In the so-called Fire Sermon (Āditta-pariyāya) (Vin I, 34-5; SN 35.28) the Buddha tells the bhikkhus that everything is on fire. By everything he tells them he means the five senses plus the mind, their objects, and the operations and feelings they give rise to - i.e. everything means the totality of experience. All these are burning with the fires of greed, hatred and delusion.
In the nidana chain, then, craving creates fuel for continued burning or becoming (bhava). The mind like fire, seeks out more fuel to sustain it, in the case of the mind this is sense experience, hence the emphasis the Buddha places on "guarding the gates of the senses". By not being caught up in the senses (appamāda) we can be liberated from greed, hatred and delusion. This liberation is also expressed using the fire metaphor when it is termed nibbāna (Sanskrit: Nirvāṇa) which means to "go out", or literally to "blow out". (Regarding the word Nirvāṇa, the verb vā is intransitive so no agent is required.)
Probably by the time the canon was written down (1st Century BCE), and certainly when Buddhaghosa was writing his commentaries (4th Century CE) the sense of the metaphor appears to have been lost, and upādāna comes to mean simply "clinging" as above. By the time of the Mahayana the term fire was dropped altogether and greed, hatred and delusion are known as the "three poisons".

source:
http://en.wikipedia.org/wiki/Up%C4%81d%C4%81na