Vers
 VEDA 
jñānena tu tad ajñānam yeṣāṃ nāśitam ātmanaḥ | teṣām ādityavaj jñānaṃ prakāśayati tat param
“As the sun dispels darkness and illuminates everything, so divine knowledge destroys ignorance and reveals the transcendental Absolute Truth.” — Bhagavad-Gītā 5.16    

Five topics of knowledge

Five topics of knowledge (tattva) dealt with in Bhagavad-gītā and other Vedic scriptures are:

  1. karma (actions, deeds)
  2. kāla (time)
  3. prakṛti (the material nature)
  4. jīva (the individual spiritual soul)
  5. īśvara (the Supreme Lord)

1. Karma

Karma can be divided threefold into karma, akarma, vikarma (and fourfold into karma, akarma, vikarma and ugra-karma).

Karma refers to pious actions, the performance of prescribed duties (in the varnāśrama-dharma) and activities that do not contradict the rules and regulations prescribed in the scriptures for civilised human existence in the varnāśrama, the Vedic social system. Such activities produce happy, favourable living conditions.

Akarma means (1) non-action, inactivity, (2) not performing pious actions, the omission of prescribed actions (duties in varnasrama-dharma), (3) but also actions whose fruits one offers to the Supreme Lord are called akarma.

Vikarma means forbidden or sinful actions, that is, actions that contradict the regulations of the scriptures. Such activities and also omitted duties create difficult life circumstances, misfortune, suffering.

Destructive activities found everywhere nowadays (environmental destruction; bombings; wars; inordinate exploitation of mineral resources; factory farming and animal slaughter; the manufacture, distribution and consumption of addictive, degrading intoxicants; etc. etc.) are called ugra-karma. Ugra-karma leads to hellish living conditions.

yajñārthāt karmaṇo 'nyatra loko yam karma-bandhanaḥ | tad-arthaṃ karma kaunteya mukta saṅgaḥ samācara
“Actions should be performed as sacrifices to Viṣṇu, otherwise they bind the doer to the material world. Therefore, O son of Kunti, perform your prescribed duties to His satisfaction. In this way you will always be unattached and remain free from attachment.”
— Bhagavad-Gītā 3.9

2. Kāla

“The time factor, which causes the transformation of the various material manifestations, is another aspect of the Supreme Personality of Godhead. Anyone who does not know that time is the same Supreme Personality is afraid of the time factor.”
— Śrīmad-Bhāgavatam 3.29.37

Kāla, the time factor, the eternal time, is an aspect of the Supreme Lord. Time initiates and destroys the creation of the material world. Time is measured by movement in space, beginning with the movement of atoms (the smallest unit of time) to the movement of the sun in the universe. The sun moves in a fixed orbit in the universe. Such an orbit is a year on Earth and a day and night on the planets of the demigods. The next larger unit of time is a catur-yuga (4,320,000 years) consisting of four yugas (sattva-, treta-, dvāpara-, kali-yuga), 1000 catur-yugas form a kalpa or a day of Brahmās, the creator deity. His night lasts the same length of time. Brahmā's life lasts 100 years. If you multiply these numbers together, you get the duration of the universe according to earthly time reckoning. For Mahā-Viṣṇu, Brahmā's life lasts as long as a single breath of his.

“Eternal time is the controller of various dimensions, starting from that of the atom to the immensely long halves of Brahmās' lifetime; nevertheless, it is controlled by the Supreme Lord. Time can only rule those who identify themselves with a material body, even if they live on Satyaloka or other higher planets of the universe.”
Śrīmad-Bhāgavatam 3.11.39

In time, living beings act in the material world and enjoy or suffer the fruits of their actions. In the Mahābhārata, Indra, the king of the heavenly planets, says to Bali Mahārāja, after defeating him in a battle between devas (demigods) and daityas (demons), tied him up and threw him into a cave:

“Verily, because of your strength of soul, you are unmoved in need today. What person would still put faith in his body or the objects of desire after realising the fleeting nature of all things in the universe? Like you, I know that the universe is not eternal and that it burns in the fire of time. Everyone is haunted by time. All things are fried in the pan of time. Time has no master. Time is ever vigilant; no one can escape it. As the current of a river washes away a tree whose roots it reaches, so time sweeps away the one who says 'this I will do today and that I will do tomorrow'. Time sweeps one away and men exclaim: 'I saw him a little while ago. How did he die?' Wealth, comfort and good position in society – they all become victims of time. Time robs all living things of their life. All things that proudly raise their heads are destined to fall. That which exists is only another form of non-existence. Everything is temporary and impermanent. Time is strong and sweeps away everything without distinction. Someone who is dragged by time is not aware of the noose in which his neck is stuck. People are confused by jealousy, vanity, lust, anger, fear, desire, heedlessness and pride. You, however, possess wisdom and renunciation. You see time as clearly as an emblem on your hand.”

And in the Śrīmad-Bhāgavatam the Supreme Lord as Kapiladeva instructs His mother Devahuti with the words:

“Just as a mass of clouds does not know the mighty influence of the wind, so one who is engaged in material consciousness does not know the mighty strength of the time factor by which he is carried away.
Whatever the materialist creates with great effort and labour for so-called happiness the Supreme Personality of Godhead destroys as the time factor, and for this reason the conditioned soul laments.
The misguided materialist does not know that his body is transitory and that the attraction to things like home, land and wealth, which are in relation to that body, is also transitory. Out of ignorance alone he thinks everything is permanent.”
— Śrīmad-Bhāgavatam 3.30.1–3

3. Prakṛti

The unmanifested state of material energy is called pradhana and the manifested state prakṛti. From prakṛti, the material nature, emerge all things in the universe, all bodies of living beings. Personified, this energy is known as Durga, Kālī and others. Prakṛti means “that which is enjoyed”. The counterpart is puruṣa, the lord and enjoyer. Since the living entities in the material world try to enjoy the manifestations of material nature, they are called puruṣa. From the spiritual point of view, however, they are also prakṛti because by their nature they are servants of the Supreme Lord and not enjoyers. The Supreme Lord, the Personality of Godhead, is the one and only puruṣa. He impregnates prakṛti with the spiritual souls by casting His glance over it. The Supreme Personality of Godhead has no direct contact with the material energy. In the form of Śiva, He unites with Durga and thus creates the living entities in the material world and their living conditions.

Prakṛti consists of 24 elements: 5 mahābhūtas (earth, fire, water, air, space), 5 knowledge acquiring senses (skin, ears, eyes, nose, mouth), 5 working senses (hands, legs, genital, rectal, speech organ), 5 indriyārthas (sense objects – touch, sound, form/colour, smell, taste), ahaṅkāra (false ego), buddhi (intelligence), manas (mind), avyakta (the unmanifest).

Prakṛti serves the Supreme Lord by providing an opportunity for spiritual souls who have turned away from Him to correct their false consciousness that they are masters and enjoyers, and to return to the spiritual kingdom of God where, according to their innermost nature, they act as servants of the Lord and enjoy with Him.

How the transformations of material energy arise from pradhana is described in the chapter "The Creation of the Material World".

4. Jīva

There are innumerable jīvas, spiritual souls. They are tiny particles of the Supreme Soul, the Personality of Godhead. Each individual soul has the option of either turning towards the Supreme Lord or turning away from Him. That is its freedom. If it turns away from Him and wants to enjoy separately from Him, it enters the material world and there – as a result of its deeds arising from the impure mind – it suffers birth, old age, disease and death again and again in different bodies. This imprisonment in the material world is ended when the conditioned soul, with purified consciousness, surrenders completely to the Supreme Lord by engaging in His transcendental service.

In the third Canto of Śrīmad-Bhāgavatam it is said:

ahaṃ mamābhimānotthaiḥ kāma-lobhādibhir malaiḥ | vītaṃ yadā manaḥ uddham aduḥkham asukhaṃ samam |
tadā puruṣa ātmānam kevalaṃ prakṛteh paraṃ | nirantaraṃ svayaṃ-jyotir animānam akhaṇḍitam
“When one is completely purified from the impurities of lust and greed arising from the false identification of the body as “I" and physical possessions as “mine", the mind becomes purified. In this pure stage he transcends so-called material happiness and suffering.
Then the soul can recognise itself as transcendental to material existence and as always self-luminous, never separate, though tiny in size.”
— Śrīmad-Bhāgavatam 3.25.16-17

A.C. Bhaktivedanta Swami Prabhupāda explains these verses in his translation of the Bhāgavatam as follows:

„In the state of pure consciousness, or Kṛṣṇa consciousness, one can see himself as a minute particle nondifferent from the Supreme Lord. As stated in Bhagavad-gītā, the jīva, or the individual soul, is eternally part and parcel of the Supreme Lord. Just as the sun's rays are minute particles of the brilliant constitution of the sun, so a living entity is a minute particle of the Supreme Spirit. The individual soul and the Supreme Lord are not separated as in material differentiation. The individual soul is a particle from the very beginning. One should not think that because the individual soul is a particle, it is fragmented from the whole spirit. Mayavada philosophy enunciates that the whole spirit exists, but a part of it, which is called the jīva, is entrapped by illusion. This philosophy, however, is unacceptable because spirit cannot be divided like a fragment of matter. That part, the jīva, is eternally a part. As long as the Supreme Spirit exists, His part and parcel also exists. As long as the sun exists, the molecules of the sun's rays also exist.

The jīva particle is estimated in the Vedic literature to be one ten-thousandth the size of the upper portion of a hair. It is therefore infinitesimal. The Supreme Spirit is infinite, but the living entity, or the individual soul, is infinitesimal, although it is not different in quality from the Supreme Spirit. Two words in this verse are to be particularly noted. One is nirantaram, which means “nondifferent” or “of the same quality”. The individual soul is also expressed here as animanam. Animanam means “infinitesimal”. The Supreme Spirit is all-pervading, but the very small spirit is the individual soul. Akhanditam means not exactly “fragmented“ but “constitutionally always infinitesimal.” No one can separate the molecular parts of the sunshine from the sun, but at the same time the molecular part of the sunshine is not as expansive as the sun itself. Similarly, the living entity, by his constitutional position, is qualitatively the same as the Supreme Spirit, but he is infinitesimal.”

5. Īśvara

Īśvara, the Supreme Lord, is omniscient, while jīva possesses only limited knowledge. Both are eternal beings and possess spiritual qualities. They are alive, possess personality and are aware of their identity.

Īśvara is totally independent. He is master of all energies. He incarnates in the universe and controls it. He grants both material enjoyment and ultimate liberation to the spiritual souls who dwell in material bodies. Though one, He manifests in many forms. Those who know transcendental science declare that Īśvara is not different from His own transcendental forms and His attributes. He cannot be perceived with material senses, but through bhakti, devotional service. He is unchanging. He reveals His own spiritual, blissful form to His pure devotees who serve Him in devotion and are free from dualities and the contamination of the three modes of material nature.

Brahman, paramātmā, bhagavan are three aspects of the Supreme Being, the Absolute Truth. He is experienced in these aspects, according to the desire or view of living beings.

Brahman is undifferentiated, without form, without qualities. Brahman is the impersonal aspect of the Supreme Being, the effulgence or radiation of His transcendental body. Brahman is actually indescribable, being without qualities. Brahman-realisation is experienced as liberation, as dazzling light and as unity-consciousness.

Paramātmā is the Supreme Soul (Viṣṇu), the Soul of the universe and the Supersoul in the heart of every living being. Paramātmā accompanies the conditioned souls in their migration in this world from one body to another. He is the witness and the permitter of their deeds. “I dwell in the heart of every living being; from me come remembrance, knowledge and forgetfulness . . . .” says the Supreme Lord in the Bhagavad-Gītā.

“However, there is another in the body, a transcendental enjoyer, and this is the Lord, the supreme possessor, who is present as observer and as permitter, and who is called the Supersoul.”
— Bhagavad-Gītā 13.23
“She is the source of light in all luminaries. She is beyond the darkness of matter and is unmanifest. She is the knowledge, She is the object of knowledge and She is the goal of knowledge. She is in the heart of everyone.”
— Bhagavad-Gītā. 13.18
“Some realise the Supersoul inside them through meditation (dhyāna), others through the development of knowledge (sankhya yoga), and still others through activities without fruitive desires (karma-yoga).”
— Bhagavad-Gītā 13.25

In the Upanishads there is a beautiful allegory for the situation and relationship of the Supersoul and the living being. There, paramātmā and jīva are compared to two birds sitting on a tree (the body or material world). One bird eats of the sweet and bitter fruits of the tree – that is, it enjoys and suffers the pleasant and unpleasant results of its actions (karma) – and the other bird, completely unattached, watches it.

Bhagavan is the Personality of Godhead. Bhagavan means “the one who possesses all six opulences (strength, beauty, fame, wealth, knowledge and renunciation) unlimitedly in perfection”. The Bhagavan aspect is superior to the Paramātmā and Brahman aspects.

“Kṛṣṇa, who is known as Govinda, is the supreme controller. He possesses an eternal, blissful, spiritual body. He is the cause of all causes. He Himself has no cause.” (Brahma-Saṃhitā 5.1)
“I worship Govinda, the primordial Lord, whose effulgence is the origin of the undifferentiated, indivisible, unlimited brahman, from which innumerable material universes with their various abundances emerge.” (Brahma-Saṃhitā, verse 40)
“O Lord, that You are eternally manifested as the impersonal brahman is neither particularly wonderful nor very significant. Your really important aspect is Your personal form. By Your own transcendental power we are now enabled to see You. How fortunate we are now to see You! O Lord, You are not visible to the wicked, though You dwell in the heart of every living being. As for us – we can see You face to face, though You are unlimited!” (A verse from the Śrīmad-Bhāgavatam (3.15.50) spoken by the four saints known as Kumaras)

The Personality of Godhead, the Supreme Lord, is attractive even to liberated souls who have realised brahman or paramātmā because of His transcendental beauty and His other qualities. The sight of Him is most gratifying; even more gratifying is serving Him through sravanam (hearing about the Lord), kirtanam (speaking about the Lord; chanting His holy names, etc.), smaranam (remembering the Lord, thinking of Him), arcana (worshipping His transcendental images in temples) and other processes of service. Such loving devotion is the perfection of life.

The form of the Lord can only be perceived with spiritual senses by the grace of the Lord and only by those jīvas who have overcome the influence of the three modes of material nature, are like-minded to all living beings and are engaged in the loving service of the Supreme Lord.

“Through devotional service one may be enabled to see the Supreme Personality of Godhead face to face, to understand Him with the mind and to perceive Him in the heart through meditation.”
Vedānta-sutra 3.2.24

Those who offer uninterrupted devotional service to the Lord enjoy the greatest bliss and are free from all fear. In the Śrīmad-Bhāgavatam, the four Kumaras who could see Narayana face to face pray:

“O Lord, we pray that You may allow us to take birth in hellish conditions of life as long as our hearts and minds are always engaged in Your service, our words are beautiful (by speaking of Your glory) as Tulasi leaves are beautified when offered to Your lotus feet, and as long as our ears are filled with the sound of singing Your transcendental attributes.”
— Śrīmad-Bhāgavatam 3.15.49)

In other words, the Kumaras do not care whether they take birth on heavenly planets, hellish planets or on earth, as long as they can engage in devotional service to the Lord and do not forget Him. Devotional service to the Supreme Personality of Godhead, even in hellish circumstances, is more desirable than liberation in the impersonal brahman.

Summary

The Vedic scriptures are the only source of knowledge about the Absolute Truth. No scripture outside the Vedic culture explains the Absolute Truth in its three aspects, let alone knowledge about the Personality of Godhead. Śrī Kṛṣṇa is the original Personality of Godhead (kṛṣṇas tu bhagavan svayam..., īśvarah paramah kṛṣṇah....). Everything emanates from Him and is permeated by Him. In the Bhagavad-Gītā (15.15), the Lord says that He is the goal of Vedic knowledge, that He is the author of the Vedānta-sutra and that He is the knower of the Vedas. He is the Master of innumerable energies. Ignorant philosophers of religion, due to dualistic view and lack of intelligence, argue whether God is a person, separate from everything, or whether He is everything without personality. From the Vedic scriptures we learn that Bhagavan is incomprehensibly simultaneously one with everything and yet different from everything (acintya bhedabheda tattva). He alone can liberate the conditioned souls in the material world from all sufferings. Demigods like Brahmā, Śiva, Surya, Indra etc. can grant blessings to people through which they can gain material benefits, but not ultimate liberation and love for God.

The many jīvas (spiritual souls) live in different conditions of existence in the material and spiritual worlds. There are two types of jīvas: nitya-siddhas (eternally liberated souls) and nitya-bandhas (eternally conditioned souls). Jivas who are inclined to the Supreme Lord from the beginning (nitya-siddhas) live eternally in the spiritual world. Jivas who are averse to the Personality of Godhead are bound by illusion and live in the material world. Other nitya-bandhas eventually turn to Him and eventually become free from the bondage of material illusion, which hides the form and qualities of the Lord. By the grace of the Lord, they are enabled to see the Personality of Godhead face to face.

Karma is temporary – its beginning cannot be traced, but it has an end when the living being attains liberation through devotion to the Supreme Lord. The four tattvas Īśvara, jīva, prakṛti and kāla are eternal.

In the vedic scriptures it es stated:

nityo nityānāṃ cetanaś cetanānām eko bahunāṃ yo vidadhāti kāmān
“Among all eternal living beings there is one Supreme Living Being. Among all conscious beings there is a Supreme Conscious Being who maintains all living beings since time immemorial.”
— Śvetaśvatara Upaniṣad 6.13
gaur anady anantavati – “Prakṛti is like a cow that was never born and never dies”.
— Culika Upaniṣad, Mantra 5

The jīvas, prakṛti and kāla are subordinate to īśvara and are under His control. This is confirmed in the Śvetaśvatara Upaniṣad:

sa viśva-kṛd viśva-vid ātmā-yonir jñah kāla-karo guṇi sarva-vid yaḥ | pradhana-kṣetrajña-patir guṇesah saṃsāra-mokṣa-sthiti-bandha-hetuh
“The Supreme Personality of Godhead is the Creator of the material universes. He is the Creator of all that exists in the universes. He is the Father of all living beings. He is the creator of time. He is full of transcendental virtues. He is omniscient. He is the Master of pradhana, the unmanifest material nature. He is the Master of the guṇas, the three modes of material nature. He is ksetrajnah, the Master of the individual spiritual souls dwelling in material bodies. He binds the conditioned souls to the material world and He is also their liberator.”
— Śvetaśvatara Upaniṣad 6.16