But, strictly speaking, upâdâna is the grasping at life or pleasure: taṇhâ is the incessant, unsatisfied craving which causes it. It is compared to the birana, a weed which infests rice fields and sends its roots deep into the ground.

Its doctrine of Trishna and Upadana. 3. Its theory of Kharma. 4. Its doctrine of Nirvana. The Skandas, five in number, constitute in their interaction what all others than Buddhists regard as the soul. They consist of material properties; the senses; abstract ideas; tendencies or propensities; and the mental powers.

Existence cannot continue without the clinging to life, just as fire cannot continue without fuel . The clinging in its turn depends on Taṇhâ, the thirst or craving for existence. The distinction between taṇhâ and upâdâna is not always observed, and it is often said taṇhâ is the cause of karma or of sorrow.

It then becomes uncontrollable and is clearly a matter of guilt. Now, the momentum of this Upadana is such that it cannot be arrested by death. Like the demons of Gadara it must again become incarnate, even though it should enter the body of a brute.

The roots engender contact; contact again brings forth sensation; sensation brings forth longing desire; longing desire produces upâdâna. Upâdâna is the cause of deeds; and these again engender birth; birth again produces age and death; so does this one incessant round cause the existence of all living things.

Trishna is that inborn element of desire whose tendency is to lead men into evil. So far, it is a misfortune or a form of original sin. Whatever it may have of the nature of guilt hangs upon the issues of a previous life. Upadana is a further stage in the same development. It is Trishna ripened into intense craving by our own choice and our own action.

We seem here on the threshold of the deepest problems but the answer, though of wide consequences, brings us back to the strictly human and didactic sphere. Existence depends on Upâdâna. This word means literally grasping or clinging to and should be so translated here but it also means fuel and its use is coloured by this meaning, since Buddhist metaphor is fond of describing life as a flame.

They were not self-caused, they were not personal existences, nor were they either uncaused; then, as one who breaks the first bamboo joint finds all the rest easy to separate, having discerned the cause of birth and death, he gradually came to see the truth; deeds come from upâdâna, like as fire which catches hold of grass; upâdâna comes from trishnâ, just as a little fire inflames the mountains; trishnâ comes from vedanâ, the perception of pain and pleasure, the desire for rest; as the starving or the thirsty man seeks food and drink, so "sensation" brings "desire" for life; then contact is the cause of all sensation, producing the three kinds of pain or pleasure, even as by art of man the rubbing wood produces fire for any use or purpose; contact is born from the six entrances.