Understanding the creation: Mahat-tattva, causal ocean, pradhāna, prakrit... what is the difference?
The creation of the Lord is extremely complex. We can't even properly understand the universe we live in. Vast as it may seem, our universe is just one in billions of other universes.
The creation of the Lord is extremely complex. We can't even properly understand the universe we live in—both scientists and students of the Vedas are baffled in trying to understand the details, and vast as it may seem, our universe is just one in billions of other universes that are simultaneously created by the Lord. All these universes float in an even greater structure, which is the mahat-tatva, and this exists on the top of an even bigger structure, which is the causal ocean. All of this together forms just one quarter of the creation, the rest being the spiritual world. Therefore, we can't even comprehend how vast the creation may be.
This is described in a summary form by Srila Prabhupada in his summary to CC Adi 5:
"Outside of the Vaikuṇṭha planets is the impersonal manifestation of Śrī Kṛṣṇa, which is known as Brahmaloka. On the other side of Brahmaloka is the spiritual kāraṇa-samudra, or Causal Ocean. The material energy exists on the other side of the Causal Ocean, without touching it. In the Causal Ocean is Mahā-Viṣṇu, the original puruṣa expansion from Saṅkarṣaṇa. Mahā-Viṣṇu places His glance over the material energy, and by a reflection of His transcendental body He amalgamates Himself within the material elements.
As the source of the material elements, the material energy is known as pradhāna, and as the source of the manifestations of the material energy it is known as māyā. But material nature is inert in that she has no independent power to do anything. She is empowered to make the cosmic manifestation by the glance of Mahā-Viṣṇu. Therefore the material energy is not the original cause of the material manifestation. Rather, the transcendental glance of Mahā-Viṣṇu over material nature produces that cosmic manifestation.
Mahā-Viṣṇu again enters every universe as the reservoir of all living entities, Garbhodakaśāyī Viṣṇu. From Garbhodakaśāyī Viṣṇu expands Kṣīrodakaśāyī Viṣṇu, the Supersoul of every living entity. Garbhodakaśāyī Viṣṇu also has His own Vaikuṇṭha planet in every universe, where He lives as the Supersoul or supreme controller of the universe. Garbhodakaśāyī Viṣṇu reclines in the midst of the watery portion of the universe and generates the first living creature of the universe, Brahmā. The imaginary universal form is a partial manifestation of Garbhodakaśāyī Viṣṇu.
On the Vaikuṇṭha planet in every universe is an ocean of milk, and within that ocean is an island called Śvetadvīpa, where Lord Viṣṇu lives. Therefore this chapter describes two Śvetadvīpas-one in the abode of Kṛṣṇa and the other in the ocean of milk in every universe. The Śvetadvīpa in the abode of Kṛṣṇa is identical with Vṛndāvana-dhāma, which is the place where Kṛṣṇa appears Himself to display His loving pastimes. In the Śvetadvīpa within every universe is a Śeṣa form of Godhead who serves Viṣṇu by assuming the form of His umbrella, slippers, couch, pillows, garments, residence, sacred thread, throne and so on."
The center of the whole creation is Goloka Vrindavana, the inconceivably vast, lotus-shaped planet where the Lord performs His intimate pastimes surrounded by His perfect devotees. Goloka Vrindavana is bigger than all other spiritual planets combined; therefore, we can't even imagine how extensive it may be. Each of the petals of this gigantic Lotus is like a separate planet, where many pastimes happen simultaneously.
Around this gigantic lotus-shaped planet, there are innumerable Vaikuṇṭha planets, where the Lord exhibits His opulence in many Viṣnu forms. Each of these Vaikuṇṭha planets is much bigger than a material universe, and therefore, they are also inconceivably big, with each planet being the abode for an unlimited number of souls.
Around all these spiritual planets is the impersonal Brahmajyoti, the spiritual light that emanates from Krsna's body and from all the spiritual planets. This spiritual light, which is the abode of all kinds of impersonalists, hides the spiritual planets from the view of all the souls who haven't developed their natural attitude of service to the Lord.
In a corner of this vast spiritual light, the Lord creates an ocean of spiritual water and lies there as Mahā-Viṣnu. This ocean of spiritual waters is called the Causal Ocean, or Kārana Ocean, and because He lies on this ocean, Lord Mahā-Viṣnu is also called Kāraṇodakaśāyī Viṣnu, or Kāraṇārṇavaśāyī Viṣnu.
On his purport to SB 1.3.2, Prabhupada describes:
"The Mahā-Viṣṇu lies down in some part of the spiritual sky by His own free will. Thus He lies on the ocean of kāraṇa, from where He glances over His material nature, and the mahat-tattva is at once created. Thus electrified by the power of the Lord, the material nature at once creates innumerable universes, just as in due course a tree decorates itself with innumerable grown fruits. The seed of the tree is sown by the cultivator, and the tree or creeper in due course becomes manifested with so many fruits. Nothing can take place without a cause. The Kāraṇa Ocean is therefore called the Causal Ocean. Kāraṇa means "causal." We should not foolishly accept the atheistic theory of creation. The description of the atheists is given in the Bhagavad-gītā. The atheist does not believe in the creator, but he cannot give a good theory to explain the creation. Material nature has no power to create without the power of the puruṣa, just as a prakṛti, or woman, cannot produce a child without the connection of a puruṣa, or man."
The next stage is what is called pradhāna. Lord Kapila describes it in the Srimad Bhagavatam (3.26.10), Lord Kapila describes its nature:
yat tat tri-guṇam avyaktaṁ, nityaṁ sad-asad-ātmakam
pradhānaṁ prakṛtiṁ prāhur, aviśeṣaṁ viśeṣavat"The Supreme Personality of Godhead said: The unmanifested eternal combination of the three modes is the cause of the manifest state and is called pradhāna. It is called prakṛti when in the manifested stage of existence."
In his purport, Prabhupada explains: "The Lord points out material nature in its subtle stage, which is called pradhāna, and He analyzes this pradhāna. The explanation of pradhāna and prakṛti is that pradhāna is the subtle, undifferentiated sum total of all material elements. Although they are undifferentiated, one can understand that the total material elements are contained therein. When the total material elements are manifested by the interaction of the three modes of material nature, the manifestation is called prakṛti."
Pradhāna is the avyakta-prakṛti of the Lord, material energy in its unmanifested form, where the three modes of material nature reside in equilibrium. Pradhāna is thus different from the causal ocean, which is an expansion of the Lord's spiritual potency.
As declared by Lord Brahma on the Srimad Bhagavatam (10.14.14), and also on the Brahma-saṁhitā (5.47), the causal ocean is the abode of Mahā-Viṣnu, where he lies while performing His pastime of creating the material universes. The causal ocean is the border between the material creation and the spiritual world, like a barrier of water separating the material and spiritual. When Lord Vāmanadeva pierces the shell of the universe with His toe, the crack cuts through all coverings and reaches the spiritual waters of the causal ocean, which flows into the universe, manifesting in the form of the waters of the river Ganges.
The pradhāna, on the other hand, manifests from the Lord's external potency (bahirāṅgā śakti); it is compared to a cloud that floats on the causal ocean, remaining inert until activated by the look of Mahā-Viṣnu. This transcendental look contains the creative potency of the Lord, including the time energy, which puts pradhāna into movement, breaking the equilibrium, and making the three modes distinct. This starts the process of creation, with the three modes being progressively combined with the time energy, generating the material elements, quick-starting the material creation.
From this point, pradhāna is called prakṛti (or mahat-tattva), the manifested material nature, which serves as the foundation for the material creation. This process is mentioned in several of the Puranas (including the Srimad Bhāgavatam) and also in the Srimad Bhagavatam. It is also studied in the atheistic Sankhya, which incorrectly concludes that pradhāna (and not the Lord) is the ultimate cause of the material manifestation.
Although the pradhāna and the mahat-tattva (prakṛti) are called material, they are in reality formed from the same spiritual energy that forms the Causal Ocean. The energy is just assembled in a certain way. The reason they are considered material, different from the Causal Ocean, which is taken as fully spiritual, is that pradhāna and the mahat-tatvā exist under the realm of Maya, the illusory potency of the Lord, which allows the conditioned souls to see the energy as matter and play with it.
This is explained by Krsna himself on ŚB 2.9.34:
ṛte ’rthaṁ yat pratīyeta, na pratīyeta cātmani
tad vidyād ātmano māyāṁ, yathābhāso yathā tamaḥ"O Brahmā, whatever appears to be of any value, if it is without relation to Me, has no reality. Know it as My illusory energy, that reflection which appears to be in darkness."
In other words, all the potencies of the Lord are in truth spiritual. The external potency appears to be material just due to the ignorance of the conditioned souls. When this ignorance is removed, one can see the Lord everywhere, even if still technically living in the material world.
This also explains why, on some purports, Prabhupada equates the Mahat-tattva with the causal ocean. The difference between them is actually merely technical.
The permutation of pradhāna into prakṛti leads to the appearance of the material universes, the final stage of the material creation, which forms a gigantic structure that floats on the waters of the causal ocean, without, however, mixing with it. This collective of all material universes is sometimes compared to a mass of foam, or a plaque of styrofoam floating on top of it.
Inside each material universe, the Lord manifests Himself as Garbhodakaśāyī Viṣnu, creating a cosmic ocean that fills about half of the universe and lies on top of it on the bed of Śeṣa Nāga. Comfortably situated, He manifests a lotus flower from his navel, from where Brahma appears. Simultaneously, He expands Himself as Kṣīrodakaśāyī Viṣnu, and enters into all material elements and in the hearts of all as Paramātmā, powering the whole creation.
A soul who attains liberation has to cross over all these coverings, reaching the eternal abode of the Lord, which is far beyond and fully transcendental.