Before we go into the question of [No Soul] proper, it is useful to have a brief idea of the Conditioned Genesis. The principle of this doctrine is given in a short formula of four lines:

When this is, that is (Imasmip sali idap hoti) ;
This arising, that arises (Imassuppādā idaṃ uppajjati);
When this is not, that is not (Imasmiṃ asati idaṃ na hoti);
This ceasing, that ceases (Imassa nirodhā idaṃ nirujjhati).

On this principle of conditionality, relativity and interdependence, the whole existence and continuity of life and its cessation are explained in a detailed formula which is called Paṭicca-samuppāda ‘Conditioned Genesis,’ consisting of twelve factors:

1. Through ignorance are conditioned volitional actions or karma-formations (Avijjāpaccayā saṃkhārā).
2. Through volitional actions is conditioned consciousness (Saṃkhārapaccayā viññāṇaṃ).
3. Through consciousness are conditioned mental and physical phenomena (Viññāṇapaccayā nāmarūpaṃ).
4. Through mental and physical phenomena are conditioned the six faculties (i.e., five physical sense-organs and mind) (Nāmarūpapaccaya satāyatanaṃ).
5. Through the six faculties is conditioned (sensorial and mental) contact (Saḷāyatanapaccayā phasso).
6. Through (sensorial and mental) contact is conditioned sensation (Phassapaccayā vedanā).
7. Through sensation is conditioned desire, ‘thirst’ (Vedanāpaccayā taṇhā).
8. Through desire (‘thirst’) is conditioned clinging (Taṇhāpaccayā upādānaṃ).
9. Through clinging is conditioned the process of becoming (Upādānapaccayā bhavo).
10. Through the process of becoming is conditioned birth (Bhavapaccayā jāti).
11. Through birth are conditioned
12. decay, death, lamentation, pain, etc. (Jātipaccayā jarāmaraṇaṃ).

This is how life arises, exists and continues. If we take this formula in its reverse order, we come to the cessation of the process:

Through the complete cessation of ignorance, volitional activities or karma-formations cease; through the cessation of volitional activities, consciousness ceases; through the cessation of birth, decay, death, sorrow, etc., cease.

It should be clearly remembered that each of these factors is conditioned (Paṭiccasamuppanna) as well as conditioning (paṭicca samuppāda). Therefore they are all relative, interdependent and interconnected, and nothing is absolute or independent; hence no first cause is accepted by Buddhism as we have seen earlier. Conditioned Genesis should be considered as a circle, and not as a chain.