The Four Philosophical Schools
Seeds of the Four Philosophical Schools
by Khenpo Ngawang Palzang
Homage to the glorious noble master, who possesses vast, non-referential compassion!
Here, I shall briefly explain the seeds of the four philosophical schools.
First, there are the two truths (or levels of reality) according to the śrāvaka school of Vaibhāṣika. The Treasury of Abhidharma says:
Things which, when destroyed or mentally dissected,
Can no longer be identified by the mind,
Such as pots or water, are relative;
All else besides is ultimately existent. 
As this indicates, any coarse entity that could either be smashed to pieces with an object such as a hammer or mentally dissected, so that a mind apprehending the coarse appearance would no longer identify it as such, belongs to the relative level of reality. As concerns the ultimate, any given material thing or state of consciousness may be divided into component particles or moments, and the ultimate constituents of coarse matter are partless particles, while the ultimate constituents of cognitive phenomena are indivisible moments of consciousness. Neither can be further divided by the apprehending mind; they thus correspond to ultimate reality.
The Commentary on Valid Cognition says:
That which can perform a function
Is here said to be ultimately existent.
That which cannot perform a function
Is said to be relatively existent.
These are the specifically and generally characterized.
Thus, when investigating an ultimately real, functional entity to see whether it has unique conventional characteristics, the followers of this tradition say that any specifically characterized, functional entity is ultimately real. By contrast, whatever is generally characterized and incapable of functioning is relatively real. This presentation of the two levels of reality relates only to this analysis of the presence or absence of specific conventional characteristics; it does not imply that the school has no other means of classifying the two levels of reality.
3. Cittamātra (Mind Only)
Here, all phenomena are understood in terms of three natures: the imputed, dependent and consummate. As the Ornament of Mahāyāna Sūtras says:
With the three aspects of appearances in their three aspects.
As this indicates, all phenomena included within the categories of location, sensory objects and mind are understood to be purely mental. All the perceiving and perceived phenomena of the imputed nature as well as the mind and mental phenomena of the dependent nature are deceptive, delusory phenomena of relative reality. By contrast, the essence of the dependent nature, which is naturally luminous consciousness, and the consummate nature, which is the fact that this [dependent nature] is empty of the dualistic projections of the imputed nature, included within intrinsic reality (dharmatā) and wisdom, are defined as ultimate reality.
4. Mādhyamika (Middle Way)
There are many subdivisions of the Mādhyamika, but here I shall refer only to two, Svātantrika and Prāsaṅgika.
Svātantrikas emphasize a "nominal ultimate" that relates to the post-meditation and involves assertions. Theirs is primarily an approach for individuals who progress gradually. Thus, in this system, relative reality is divided into the false and correct relative. As Two Truths explains:
The relative is divided
Into the correct and incorrect.
Specifically characterized, functional entities are here asserted to be the correct relative, while generally characterized, non-functional entities are the incorrect relative. Relative reality thus corresponds to the unexamined nature accepted in the world — that is, when there is no investigation or analysis inquiring into ultimate reality.
As regards the ultimate, Ornament [of the Middle Way] says:
These entities spoken of by ourselves and others
Are devoid of intrinsic nature, like reflections,
Because in reality they are by nature neither single nor multiple. 
According to the reasoning of 'neither one nor many' external and internal phenomena ultimately lack inherent existence. Yet while lacking true existence, they still appear unceasingly through dependent origination. Emptiness and dependent origination are thus an indivisible unity. In this natural inseparability, emptiness eliminates the extreme of nonexistence and appearance eliminates the extreme of existence. Ultimate reality is the ascertainment of this nature beyond all conceptual extremes and free from any assertion.
Any conclusions arrived at gradually concerning existence, non-existence, their unity or the freedom from the four extremes do not transcend the ordinary conceptual mind. They do not therefore constitute realization of the Middle Way beyond the mind. Eventually however, when meditation becomes transcendent and one arrives at a state beyond all assertions, the basic space that is free from conceptual constructs and ideas about how things are, this is identical to the realization of the Mādhyamika Prāsaṅgika.
The Prāsaṅgika approach is concerned with the state of meditative equipoise that is free from all assertions; it is intended primarily for individuals capable of sudden development. Here, there is a subtle object of negation, which is the Svātantrika clinging to relative existence and ultimate non-existence. This subtle form of clinging is here regarded as an object of negation. As Candrakīrti said:
We must accept relative reality, just as it is, beyond any doubts, like a container for one in search of water. 
Analysis of the relative is therefore said to be the basis. Through the four great logical arguments of the Middle Way, one then ascertains the nature of all phenomena, beyond the four or eight conceptual extremes. This means that there is no assertion that the basic nature is unborn. After all, any assertion of existence or non-existence is simply an ordinary concept. Instead, this is the approach of realization through primordial wisdom beyond the ordinary mind, having entirely pacified all conceptual constructs.
A follower of this Middle Way beyond all assertions still guides disciples during the post-meditation phase and sets out the paths and stages. All such conventional explanations of cause and effect are still feasible, since they concern illusory phenomena and how they arise interdependently and appear to those who maintain duality. Since there is appearance, there is talk of relative reality. The fact that what appears remains beyond all extremes from the moment of its appearance is ultimate reality.
There are some who say, "Here, appearances themselves are not to be refuted; it is clinging to things as real that one must overturn." On the basis of these words, these scholars propose the following interpretation of the Mādhyamika position: what is discovered through valid cognition inquiring into the conventional is relative reality, wheras what is discovered through valid cognition inquiring into the ultimate is ultimate reality. Here, relative means what is merely nominal and has only imputed existence. The term "merely nominal" counters the Svātantrika claim that there are specifically characterized entities; whereas the term "imputed existence" indicates that all phenomena are mental imputations. These imputed phenomena, which are actually unreal, are asserted to be relative reality. Ultimately, appearances are not objects of refutation; it is the clinging to them as real that is to be overcome. For example, an entity such as a pillar is not itself negated; it is its reality that must be refuted. Once the pillar's true existence is refuted this might imply non-existence, but such non-existence is not refuted. If it were, that would itself imply existence, so non-existence remains uncontoverted. The emptiness that is the negation of true existence, which is a feature of unreal things such as pillars, together with the emptiness of the composite — they constitute ultimate reality. Such is the assertion.
| Translated by Adam Pearcey, 2018
Abhidharmakośa VI, 4. ↩
Pramāṇavārttika III, 3. ↩
yul don sems. There might be an error here, as this phrase is more often glossed as gnas don lus gsum, i.e., environment, sense objects and body (or bodies). ↩
Satyadvayavibhaṅga by Jñānagarbha, verse 12. ↩
Madhyamakālaṃkāra verse 1 ↩
It is commonly said that the fact that things appear eliminates the extreme of nihilism or a belief in the total non-existence of things, and that emptiness dispels the extreme of eternalism, or the belief in things as truly existent. Here, following Tsongkhapa's statement in Three Principal Aspects of the Path, Khenpo Ngawang Palzang goes further and says that the fact that things appear dispels the extreme of taking things to be truly existent, because for things to appear they must lack inherent existence. Moreover, the fact that things are empty eliminates the extreme of non-existence, since it is only because things are empty that they can appear. ↩
From Prasannapadā. ↩