The Second Noble Truth

Origin of suffering (Samudāya)

Our day-to-day troubles may seem to have easily identifiable causes: thirst, pain from an injury, sadness from the loss of a loved one. In the second of his Noble Truths, though, the Buddha claimed to have found the cause of all suffering - and it is much more deeply rooted than our immediate worries.

The Buddha taught that the root of all suffering is desire, tanhā. This comes in three forms, which he described as the Three Roots of Evil, or the Three Fires, or the Three Poisons.
The Three Fires of hate, greed and ignorance, shown in a circle, each reinforcing the others. Photo: Falk Kienas ©

The three roots of evil

These are the three ultimate causes of suffering:

• Greed and desire, represented in art by a rooster
• Ignorance or delusion, represented by a pig
• Hatred and destructive urges, represented by a snake

Language note: Tanhā is a term in Pali, the language of the Buddhist scriptures, that specifically means craving or misplaced desire. Buddhists recognise that there can be positive desires, such as desire for enlightenment and good wishes for others. A neutral term for such desires is chanda.

The Fire Sermon

The Buddha taught more about suffering in the Fire Sermon, delivered to a thousand bhikkus (Buddhist monks).

Bhikkhus, all is burning. And what is the all that is burning?
The eye is burning, forms are burning, eye-consciousness is burning, eye-contact is burning, also whatever is felt as pleasant or painful or neither-painful-nor-pleasant that arises with eye-contact for its indispensable condition, that too is burning. Burning with what? Burning with the fire of lust, with the fire of hate, with the fire of delusion. I say it is burning with birth, aging and death, with sorrows, with lamentations, with pains, with griefs, with despairs.
The Fire Sermon (SN 35:28), translation by N̄anamoli Thera. © 1981 Buddhist Publication Society, used with permission

The Buddha went on to say the same of the other four senses, and the mind, showing that attachment to positive, negative and neutral sensations and thoughts is the cause of suffering.
http://www.bbc.co.uk/religion/religions/buddhism/beliefs/fournobletruths_1.shtml