Dependent Origination

Paṭiccasamuppāda Vibhaṅga Sutta (SN 12.2 excerpt)

Dependent Origination is the insight described by the Buddha on the occasion of his enlightenment under the Bodhi tree.

Dependent on ignorance, volitional formations arise.
Dependent on volitional formations, consciousness arises.
Dependent on consciousness, the mind-body phenomenon arises.
Dependent on the mind-body phenomenon, the six bases for the senses arise.
Dependent on the six bases for the senses, contact arises.
Dependent on contact, sensations arise.
Dependent on sensations, craving arises.
Dependent on craving, clinging arises.
Dependent on clinging, conditioned existence arises.
Dependent on moral and immoral actions in the present existence, the process of rebirth arises.
Dependent on the process of rebirth, aging and death, sorrow, lamentation, pain, grief, and despair arise.
Thus does the whole mass of suffering arise.
Through the entire cessation of ignorance, volitional formations cease.
Through the cessation of volitional formations, consciousness ceases.
Through the cessation of consciousness, name-and-form cease.
Through the cessation of name-and-form, the six sense-bases cease.
Through the cessation of the six sense-bases, contact ceases.
Through the cessation of contact, feeling ceases.
Through the cessation of feeling, craving ceases.
Through the cessation of craving, clinging ceases.
Through the cessation of clinging, existence ceases.
Through the cessation of existence, birth ceases.
Through cessation of re-birth, old age, death, sorrow, lamentation, pain, grief and despair cease.
And so on to the cessation of this whole mass of suffering.

Note-

"Now the first step, ignorance (avijja), isn’t to be under-stood as a first beginning. It’s impossible to conceive of a first beginning. The origin of suffering can only be known as an on-going process which we can understand through observing it as it works. No one, not even a Buddha, can trace this process back to a first beginning."

 Sayagyi U Chit Tin : "Knowing Anicca"