Namo tassa Bhagavato Arahato Sammasambuddhassa
Homage to the Exhalted One, Liberated One and fully Self‑Enlightened One
Patthana Pali, the seventh and last book of the Abhidhamma, is called the Maha Pakarana, the ‘Great Book’ announcing the supreme position it occupies and the height of excellence it has reached in its investigations into the ultimate nature of all the dhammas in the Universe.
The Dhammasangani gives an enumeration of these dhammas classifying them under the Tika and Duka groups. Vibhanga analyses them to show what dhammas are contained in the major categories of khandhas, ayatanas, dhatus etc. Dhatukatha studies the relationship of dhammas listed in the Matika with each component of these major categories of khandhas, ayatanas and dhatus. Yamaka resolves ambiguity in the internal and external relationship of each dhamma.
Patthana forming the last book of the Abhidhamma brings together all such relationship in a co-ordinated form to show that the dhammas do not exist as isolated entities but they constitute a well ordered system in which the smallest unit conditions the rest of it and is also being conditioned in return. The arrangement of the system is so very intricate, complex, highly thorough and complete that it earns for this treatise the reputation of being deep, profound and unfathomable.