In classical Advaita (Non-Dual) Vedanta, there are three main theories or viewpoints of reality, called shristi-dristi vada, dristi-shristi vada and lastly ajata vada. Whilst these Sanskrit words may appear complex, the idea is actually very simple, and Bhagavan Sri Ramana Maharshi explains the meaning of these terms below. 

It may be helpful to note that ‘vada’ means ‘theory’ or ‘viewpoint’, ‘shristi’ means ‘the world’ or ‘creation’, ‘dristi’ literally means ‘sight’ but in this context refers to consciousness, and ‘jata’ means ‘birth’ (or creation). Adding ‘a’ as a prefix to ‘jata’ negates the meaning so that ‘ajata’ means ‘unborn’ or ‘no creation’.

Therefore:

1) Shristi-dristi vada is the view that the world is primary and gives rise to consciousness, which is the most commonplace model of the universe, ie. that first there was a universe in which life gradually evolved on planet Earth and eventually human life and human consciousness evolved. In Western philosophy this is known as the Realist view of reality. This view also broadly corresponds to the waking state.

2) Dristi-shristi vada is the view that consciousness is primary and gives rise to the world appearance, ie. like in a dream, consciousness exists first and then this consciousness manifests the apparent dream-world and dream-subject/object duality. In Western philosophy this is known as the Idealist view of reality. This view broadly corresponds to the dream state. This view is also known as, or at least is very similar to vivarta vada, which is the view that the world and individual are both projected illusions that simultaneously appear, and that the world and individual appear to appear but do not actually appear, rather like a dream. Vivarta vada could therefore be considered to be a sub-type of Drist-Shristi-Vada.

and

3) Ajata vada is the radical view that there never was any creation at all, and that there is only The Absolute, and that there never has even been the appearance of creation. This view broadly corersponds to the deep sleep state and also to Turiya, the ‘fourth’ state. In Vivarta-vada, it is said that Maya (the entire phenomenal appearance) appears to exist, but actually doesn’t, but in ajata vada it is almost imcomprehensibly stated that Maya never even came into existence, not even as an appearance. Hence the difference between Vivarta Vada and Ajata Vada. Vivarta vada states the snake appears to exist in the dimly lit rope, but that it isn’t real, whereas ajata vada states that the snake never even appeared to exist at ‘any time’ (‘any time’ is in quotes as the notion of time and space are also ‘seen’ to never have existed).

Note that whilst (1) and (2) can be understood conceptually with the mind, Ajata vada is an advanced and highly radical teaching that is very difficult to comprehend and it makes little sense to the mind. This is why liberation is said to be unfathomable. Ajata Vada is usually associated with Gaudapada’s commentary on the Mandukya Upanishad but also features in several other scriptures such as Ribhu Gita, Yoga Vasishtha, the final few verses of Shankara’s Vivekachudamani, the Ashtavakra Gita and Avadhuta Gita to name a few. Shankara’s commentaries on the Upanishads also commonly point to the radical ajata teachings.

Vedanta teachings often start by working in a Realist framework, which is the default conceptual framework of reality for most seekers especially at the start of their journey. Then the Idealist conceptual framework is introduced, and later the Ajata or no-creation viewpoint is brought in when the seeker is ready, in step-wise progression depending on how the seeker is progressing with the teachings. The nature and content of teachings differ depending on what framework of reality is being used. Note the purpose of the teachings is not that they are true, but the view is to be adopted in order to remove ignorance and reveal THAT which cannot be taught, explained or expressed in words – THAT which you – THAT which is all there is – beyond words.

Note that the stronger the ego (ie. the identification with being a body-mind), the stronger the attachment to the belief-concept that the world is real, and this means that the higher teachings are more likely to be rejected by the ego-mind. Conversely, the weaker the attachment to body-mind, the weaker the attachment to the belief in the world being real, and the more likely the higher teachings are to be accepted. This in turn facilitates Self-Enquiry and ‘attainment’ of Moksha (liberation).

Similarly, whenever we come across a teaching, it can be very helpful to see which of the 3 levels the teaching belongs to – this can be very helpful to avoid unnecessary confusion in what can otherwise seem to be contradictory teachings.

To explain further, here is an excerpt from Day by Day with Bhagavan from 15th March, 1946:

[Ramana Maharshi:] I do not teach only the ajata doctrine. I approve of all schools. The same truth has to be expressed in different ways to suit the capacity of the hearer. The ajata doctrine says, “Nothing exists except the one reality. There is no birth or death, no projection or drawing in [of the world], no sadhaka [no seeker], no mumukshu [no one seeking liberation], no mukta [no liberated person], no bondage, no liberation. The one unity alone exists ever.”

‘To such as find it difficult to grasp this truth and who ask. “How can we ignore this solid world we see all around us?” the dream experience is pointed out and they are told, “All that you see depends on the seer. Apart from the seer, there is no seen.”

Tom: Note here how Sri Ramana is distinguishing and differentiating vivarta vada/drist-sristi vada from ajata vada. Many people erroneously think that ajata vada states that world appears as a dream and non-creation means that the world is merely a dream-like appearance (as a dream appears, but is not real, and in that sense has not been created) – ie. many people erroneously equate ajata vada with vivarta vada/dristi-sristi vada. However here in the section above, if we read carefully, we can see that Sri Ramana is stating the Ajata vada is actually different to the idea that ‘all appears as the Self’. See here and here for more on this.

In Sri Ramana Paravidyopanishad we also see this same teaching in verses 147 and 330:

147. Creation is not other than seeing; seeing and creating are one and the same process. Annihilation is only the cessation of seeing and nothing else, for the world comes to an end by the right awareness of oneself.

330. There is no creation apart from seeing; seeing and creation are one and the same. And because that seeing is due to ignorance, to cease seeing is the truth of the dissolution (of the world).

‘This is called the drishti-srishti vada, or the argument that one first creates out of his mind and then sees what his mind itself has created.

‘To such as cannot grasp even this and who further argue, “The dream experience is so short, while the world always exists. The dream experience was limited to me. But the world is felt and seen not only by me, but by so many, and we cannot call such a world non-existent,” the argument called srishti-drishti vada is addressed and they are told, “God first created such and such a thing, out of such and such an element and then something else, and so forth.” That alone will satisfy this class. Their mind is otherwise not satisfied and they ask themselves, “How can all geography, all maps, all sciences, stars, planets and the rules governing or relating to them and all knowledge be totally untrue?” To such it is best to say, “Yes. God created all this and so you see it.”’

Dr. M. said, ‘But all these cannot be true; only one doctrine can be true.’

Bhagavan said, ‘All these are only to suit the capacity of the learner. The absolute can only be one.’

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In Guru Vackaka Kovai (Garland of Guru’s Sayings), Ramana says the following (with a comment by Sri Sadhu Om):

100. Although Guru Ramana taught various doctrines according to the level of understanding of those who came to Him, we heard from Him that ‘Ajata’ alone is truly His own experience. Thus should you know.

Sri Sadhu Om’s comments: ‘Ajata’ is the knowledge that nothing – neither the world, soul nor God – ever comes into existence, and that ‘That Which Is’ ever exists as IT is.

Tom: here in Sri Sadhu Om, we have a close and direct devotee of Sri Ramana’s clearing stating what Ajata Vada actually is.

114. When the limited light [which is used to project pictures on the cinema screen] is dissolved in the bright sunlight [which enters the cinema], the pictures also will disappear instantaneously. Similarly, when the limited consciousness [chittam] of the mind is dissolved in supreme Consciousness [Chit], the picture show of these three prime entities [God, world and soul] will also disappear.

Here Sri Ramana explains why the teachings may initially concede the existence of the three primal entities (the individual or jiva, the world or jagat, and God the ordainer or Isvara):

115. Thus, since the Truth of the Source is One, why do all religions [and sometimes even Sages] start their teachings by at first conceding that these three prime entities are real? Because the mind, which is tossed about by objective knowledge, would not agree to believe in the One unless the Sages condescended to teach It as three.

122. Whatever high and wonderful state of tapas one may have attained, if one still identifies oneself with an individuality, one cannot be a Sahaja-Jnani [i.e. One in the State of Effortlessness]; one is only an aspirant of, perhaps, an advanced stage.

Here it is explained that for the teaching to ‘condescend’ to vivartha vada is the most practical method for seekers:

83. From his condescending opening words, “Because we see the world”, it is to be understood that the Great Master, Bhagavan Sri Ramana, who gives the most practical assistance to aspirants, sets aside all other doctrines and teaches that only the ‘Doctrine ofVivartha’is suitable to be taken as true.

Sri Sadhu Om’s comments: Though His experience of the Truth can only be adequately expressed by the ‘Doctrine of Ajata’, Bhagavan Sri Ramana uses only the ‘Doctrine of Vivartha’ for His Teachings…The ‘Doctrine of Vivartha’ is recommended to explain the standpoint of Advaita, ie. to explain how the world-appearance, its seer, and the seer’s knowledge of the appearance all come into existence simultaneously, unconditioned by cause and effect. However, since this accepts the appearance of the world, souls and God, it is only a working hypothesis to help aspirants. The‘Doctrine of Ajata’, on the other hand, never accepts even the appearance of this trinity, but proclaims that the One Self-shining Reality alone exists eternally and without modification; Ajata is therefore the highest of all doctrines and it is only suitable for the fully-ripened aspirants. Bhagavan Sri Ramana therefore comes down condescendingly and, setting aside ‘Ajata’ and the two lower doctrines He advocates through His Forty Verses on Reality the ‘Doctrine of Vivartha’ which is suitable for the ripe aspirants who have no faith in the lower doctrines, yet do not have the maturity to grasp the highest, ‘Ajata’.

Also see Ramana Maharshi: how to abide as the Self, the world is not real, attend to yourself

and How spiritual teachings work and Ramana Maharshi on those who claim to have surpassed the traditional notion of enlightenment

and Manonasa and The nature of Liberation | Ramana Maharshi | PDF download