Abhidharma

What it asks

Buddhist thought holds that there is no permanent self. That is a claim about what exists, and it immediately incurs a debt: something is walking around, remembering, suffering and acting.

Abhidharma pays the debt with an inventory. Reality is analysed into dharmas - the momentary constituents that are not further reducible - and everything else, including persons, chariots and forests, is a conventional designation for arrangements of them.

The result is a two-level account. It is conventionally true that you are reading this. It is ultimately true that there is no you, only a causally connected sequence of momentary events. Neither level is a mistake, and keeping them straight is what the whole system is for.

The recurring problems

What counts as ultimate. The schools produced different lists of dharmas and argued about them in enormous detail. The disagreement is not scholastic pedantry: what makes the list is precisely what the analysis takes to be irreducible.

Momentariness. If everything exists only for an instant, what makes one moment the successor of another rather than a new thing? Causal continuity has to do all the work that a persisting substance would have done, and it is not obvious it can.

Whether the past exists. One major school held that dharmas exist in past, present and future, which explains how a past action can produce a later result. Opponents held that only the present exists and had to find another mechanism. The dispute is the same one presentists and eternalists conduct now.

Whether the dharmas survive their own analysis. Nāgārjuna argued that the reasoning which dissolves persons into constituents applies equally to the constituents - that they too are empty of intrinsic nature. That objection came from within the tradition and reshaped it.

How it developed

The material begins as lists and classifications drawn from the discourses, arranged for teaching and memorisation, and becomes a systematic philosophy through the effort of making the lists consistent.

By the early centuries CE there are competing systems. The Theravāda tradition developed one in Pali; the Sarvāstivāda developed another in Sanskrit, and it was elaborated in commentaries of great length and precision.

Vasubandhu's Abhidharmakośa, in the fourth or fifth century, is the pivotal work: a summary of the Sarvāstivāda system with a commentary by the same author criticising it from a rival position. It became the standard textbook across Buddhist Asia and is still studied that way.

Nāgārjuna's critique had already opened the other line. If emptiness applies to the dharmas as well, then the Abhidharma analysis is a therapeutic stage rather than a final ontology. The subsequent Mahāyāna traditions largely took that view, while continuing to use the analysis.

The positions within it

Sarvāstivāda, Sautrāntika, Theravāda and Yogācāra each give a different systematic account; Madhyamaka critiques the enterprise from within. All are in the Schools section.

Where it stands now

Studied continuously in Buddhist monastic education for two thousand years, and read seriously by analytic philosophers since roughly the 1980s.

The comparative interest is exceptional. Reductionism about persons, the two-truths structure, mereological analysis of ordinary objects and the question of what makes a series a continuant are all live in current metaphysics, and this tradition worked on them for a millennium with different assumptions and reached conclusions that are recognisably in the same space.