I was asked by a friend to describe what achintya-bhedaabheda-tattva (inconceivable simultaneous dual/non-dualism) means. Here's my attempt to explain Vedic conclusions in my own words...
When analysing reality philosophically, there are 3 main conclusions people usually come to...
1. Nothing exists, ultimate reality is a void and what we experience here is totally illusory. We don't really exist.
2. Everything is One. Duality is illusory, in truth everything is homogenous with no distinctions.
3. Duality exists as an eternal principle of ultimate reality.
Most people think that since form and personality exist in the materialworld, they must not exist in the spiritual world. But an intelligentperson may realise that option 1 cannot be true, because here I amexisting... how does something come from nothing?
Number 2 is tricky. It sounds right, but... for the One to experienceseparation & distinction as we do, a 2nd factor necessarily needsto be involved. I'll explain: Oneness philosophers maintain that we'reall one, but a tiny particle of that Oneness (you & me) somehow oranother becomes covered by a 'cloud' of illusion that creates asubjective perspective of being separate from Source and distinct fromeach other. This philosophy sounds pretty cool and most people go forit. However, it's also flawed. The 'cloud' of illusion that createsseparation must be something OTHER than Oneness itself, because Onenesshas no defining qualities by which to create a sense of separation. Bydefinition Oneness has no distinctions, so there cannot be Oneness plusclouds. That would make it Two!
In fact, oneness cannot be aware that it exists (because if it did thenthere would be TWO things, itself and its awareness of itself), andOneness without awareness of itself doesn't exist, because who would bethere to percieve it? If it's not being percieved, for all intents andpurposes it doesn't exist. So in the end, Oneness philosophy ispractically the SAME as Nothing/Void philosophy.
None of this explains the fact that we obviously exist.
So, because we seem to be existing, duality as an aspect of absolute reality needs to be considered.
The Vedas state that the variegatedness and duality we experience inthe temporal material realm (including the etheric planes) is thereflection of a realm composed of similar items of absolute substantiality. A spiritual world.
Analogy: if you stand on the bank of a river and observe thereflection of a tree, one assumes the real thing exists independent ofthe reflection.
So the spiritual world, being the unconditioned and independent sourceof its reflection, matter, is described as a place of eternity, fullknowledge, bliss, form, activity & desire centred around Godhead,who's the whole & centre of everything whilst simultaneously anindependent personality.
The Sri Isopanisad explains: ThePersonality of Godhead is perfect and complete, and because He iscompletely perfect, all emanations from Him, such as this phenomenalworld, are perfectly equipped as complete wholes. Whatever is producedof the Complete Whole is also complete in itself. Because He is theComplete Whole, even though so many complete units emanate from Him, Heremains the complete balance.
Godhead's energies, relationships, forms, qualities, pastimes andentourage are unlimitedly variagated. The material world fractionallyreflects and represents these eternal principles of the spiritualworld, our constitutional home, not a formless blinding white light.Non-duality DOES exist, but as a secondary (subjective) aspect ofDivinity. It's known as brahman and emanates from the Godhead, permeating everything.
Inreality there IS only 1 thing: REALITY! And that reality is composed ofduality: God & God's energies (including us and this world).
Below is a purport from the Sri Isopanisad to support these statements.
In the Bhagavad-gita (14.27), the Lord explains His personal rays (brahmajyoti), the dazzling effulgence of His personal form, in this way:
brahmaṇo hi pratiṣṭhāham
śāśvatasya ca dharmasya
"I am the basis of the impersonal Brahman, which is immortal,imperishable and eternal and is the constitutional position of ultimatehappiness."
Brahman, Paramātmā and Bhagavān are three aspects of the same AbsoluteTruth. Brahman is the aspect most easily perceived by the beginner;Paramātmā, the Supersoul, is realized by those who have furtherprogressed; and Bhagavān realization is the ultimate realization of theAbsolute Truth. This is confirmed in the Bhagavad-gītā (7.7), where Lord Kṛṣṇa says that He is the ultimate concept of the Absolute Truth: mattaḥparataraḿ nānyat. Therefore Kṛṣṇa is the source of the brahmajyoti as well as the all-pervading Paramātmā. Later in the Bhagavad-gītā (10.42) Kṛṣṇa further explains:
atha vā bahunaitena
kiḿ jñātena tavārjuna
viṣṭabhyāham idaḿ kṛtsnam
ekāḿśena sthito jagat
"But what need is there, Arjuna, for all this detailed knowledge?With a single fragment of Myself I pervade and support this entireuniverse."
Thus by His one plenary expansion, the all-pervading Paramātmā, theLord maintains the complete material cosmic creation. He also maintainsall manifestations in the spiritual world. Therefore in thisśruti-mantra of Śrī Īśopaniṣad, the Lord is addressed as pūṣan, theultimate maintainer.