The Correspondence between the Five Aggregates and the Eighteen Elements Reveals the Importance of the Mental Factors (caittas) of the Manas

What are the conceptual scope and functions of the aggregate of form, the conceptual scope and functions of the aggregate of feeling, the conceptual scope and functions of the aggregate of perception, the conceptual scope and functions of the aggregate of volitional formations, and the conceptual scope and functions of the aggregate of consciousness? And what are the conceptual scope and functions of the six faculties (eye faculty, ear faculty, nose faculty, tongue faculty, body faculty, and manas), the conceptual scope and functions of the six sense objects, and the conceptual scope and functions of the six consciousnesses? What are the correspondences among them? To which of the five aggregates do the eighteen dhātus specifically correspond?

The five faculties, the five sense objects, and the mental sense object correspond to the aggregate of form. The six consciousnesses and the manas correspond to the aggregate of consciousness as well as the aggregates of feeling, perception, and volitional formations. Feeling, perception, volitional formations, and consciousness are intimately connected with the seven consciousnesses; form is also connected with consciousness, for without consciousness there would be no aggregate of form consisting of the five faculties. However, ordinary people cannot observe the aggregates of feeling, perception, volitional formations, and consciousness of the manas; even the functions of feeling, perception, volitional formations, and consciousness of the five sense consciousnesses cannot be clearly distinguished by most people. Therefore, the teachings of the Small Vehicle generally do not mention the functions of feeling, perception, volitional formations, and consciousness of the manas.

The aggregate of form is accumulated from the seeds of the four great elements, while the aggregates of feeling, perception, volitional formations, and consciousness are accumulated from the seeds of consciousness. The seeds of consciousness alone cannot perform any function; they must operate in coordination with the mental factors (caittas). Therefore, the aggregates of feeling, perception, volitional formations, and consciousness are precisely the functions of the mental factors, corresponding to the feeling mental factor, the perception mental factor, and the volition mental factor among the five universal mental factors, and also including the mental factors of mental engagement (manaskāra) and contact (sparśa). The mental factors of the six consciousnesses cannot be separated from the mental factors of the manas; if the mental factors of the manas do not operate, there would be no six consciousnesses at all, nor the mental factors of the six consciousnesses. Therefore, the five aggregates and the eighteen dhātus should correspond to one another one-to-one: the first five faculties and five sense objects correspond to the aggregate of form, while the manas, the mind consciousness, and the five sense consciousnesses correspond to the aggregates of feeling, perception, volitional formations, and consciousness. The general commander who sets all these dharmas in motion is the manas, and the supreme commander is the tathāgatagarbha.