The Dhammasangani, the Enumeration of Phenomena, opens the Abhidhamma Pitaka with the matika, a compact master list of roughly one hundred and twenty categorizing triads and dyads, wholesome, unwholesome and neutral states; states associated with pleasant, painful or neutral feeling; states that are objects of attachment or not, and so on, that functions as the classificatory grid the entire Abhidhamma method applies to analyze the whole of mental and physical experience.
The book's main body then works systematically through consciousness, breaking down each possible type of citta, or moment of consciousness, by its ethical quality, wholesome, unwholesome or neutral, and by the plane of existence it belongs to, the sense-sphere ordinary experience most beings know, the more refined form and formless spheres reached in deep meditative absorption, and the supramundane consciousness of full liberation, listing for each type the precise cluster of mental factors, feeling, perception, volition, contact and dozens more, present in that moment. Rather than narrating teaching through dialogue and story as the suttas do, the Dhammasangani presents this analysis in dense, technical, list-based prose, treating the mind not as a unified self experiencing the world but as a rapid, conditioned succession of discrete, precisely describable momentary events.