Psychology According to Darshana

Not all darshanas have the same emphasis on the 8 topics of worldview presented above and also some may deal with two or more topics together as a single cogent interconnected topic.

Similarities between darshanas:

• Current state of a person is suffering.

• A state free of suffering is attainable - this is called moksha or apavarga.

• That state of freedom is achieved through right experiential knowledge (and sometimes action).

• Purity in life which is giving up all that is contrary to the attainment of right knowledge should be given up.

• There is a moral order in the universe to which everyone should adhere to.

• Law of karma holds - good deeds lead to happiness and bad deeds lead to suffering.

In the Indian tradition, psychology is not studied as an isolated empirical science. Instead, it is treated as an essential part of philosophy (darśana), intimately connected with metaphysics, ethics, logic, and spirituality. The nature of the mind, its processes, and its transformation are discussed across all the major philosophical schools of India—not merely to understand mental behavior, but to guide the individual towards liberation (mokṣa), the highest human goal. Hence, Indian psychology is deeply integrated with soteriology—the science of freedom from suffering.

Although these six darśanas are traditionally enumerated as distinct philosophical systems, they share several core concepts, particularly within specific paired traditions—namely Sāṅkhya & Yoga, Nyāya & Vaiśeṣika, and Pūrva Mīmāṃsā & Vedānta. To streamline our analysis, we will explore six fundamental questions within the context of these paired systems, carefully noting both shared principles and divergences where they exist:

1. What is the criterion for reality and what is reality? - Metaphysics/Ontology

2. Who am I and how am I connected to that reality? - Metaphysics/Ontology

3. How do we know reality? - Epistemology

4. What is the nature of mind? - Psychology

5. What is the perfect state of happiness that I can achieve? - Soteriology

6. What role does the mind play in achieving that perfect state of happiness? - Soteriology

Although Sāṅkhya is historically one of the oldest darśanas, a logical arrangement reveals an ascending progression in philosophical transcendence. This evolution moves from Nyāya-Vaiśeṣika, which emphasizes realism and logic, to Sāṅkhya-Yoga, which integrates dualism with spiritual discipline, and finally to Pūrva-Mīmāṃsā-Vedānta, where ritualism culminates in metaphysical monism. Each darśana builds upon its predecessors, achieving a greater degree of transcendence while refining and expanding existing philosophical frameworks, illustrating the continuous evolution of Indian thought.

Nyaya & Vaisheshika

Nyāya is fundamentally the science of logic and analytic inquiry, whereas Vaiśeṣika is concerned with categorization of reality, focusing on the particularities of existence. While these two darśanas may have originated independently, they later became deeply intertwined, forming a composite philosophical system. Despite some distinctions in their classical formulations, they are now studied together due to their complementary contributions.

• Vaiśeṣika primarily focuses on ontology and cosmology, systematically classifying reality into fundamental categories.

• Nyāya, on the other hand, emphasizes epistemology, logic, and the philosophy of language, providing rigorous methods for reasoning and knowledge acquisition.

Both darśanas share a minimal emphasis on liberation (apavarga) as a core goal, instead prioritizing a structured and logical understanding of reality and knowledge.

Nyāya and Vaiśeṣika are firmly rooted in objective realism, asserting that perceived external objects possess reality independent of our mind. This stance developed in response to certain Buddhist idealist schools, which contended that external reality is either:

• A mere mental construct (vijñānavāda – consciousness manifests reality).

• A transient illusion devoid of independent existence (śūnyavāda – emptiness is fundamental).

By establishing logical realism, Nyāya-Vaiśeṣika provided counterarguments to Buddhist idealism, affirming that the external world is real and knowable through proper epistemic methods (pramāṇas).

Nyāya serves as the cornerstone of logical methodology in Indian philosophical thought. Its principles and structured reasoning techniques have been integrated into other darśanas, enabling them to construct doctrines through debate and argumentation. Because of its essential role, Nyāya is recognized within the fourteen primary branches of traditional Indian knowledge (caturdaśa-vidyāsthāna).

1. What is the criterion for reality and what is reality?

While the foundational scriptures of Nyaya and Vasisheshika do not provide an explicit definition for criterion to define reality, it can be inferred from their overarching philosophical framework. Reality is understood as prameya—an object of knowledge—that is validated through pramāṇa, the accepted methods of acquiring knowledge. Thus, anything that is cognized and affirmed by recognized epistemic processes qualifies as real.

Nyāya adopts its ontological framework directly from Vaiśeṣika, which conceptualizes reality through the lens of padārtha—a term that literally means "the meaning of a word." However, in this philosophical context, padārtha refers to any entity that can be conceived and named, implying that everything perceived and thought about constitutes reality. Vaiśeṣika advocates a pluralistic view of reality, systematically classifying it into seven fundamental categories (padārtha):

1. द्रव्य (Substance) – The foundational substratum (धर्मी) to which other categories like गुण and कर्म as धर्म inhere (समवाय) as given in a Vaisheshika sutra: 

क्रियागुणवत् समवायिकारणमिति द्रव्यलक्षणम् ॥ १.१.१५ ॥

It possesses Action and Attribute, due to being their substratum—such (is) the mark of Substance.

There are 9 kinds of द्रव्य as given in Vaisheshika sutra:

पृथिव्यापस्तेजो वायुराकाशं कालो दिगात्मा मन इति द्रव्याणि ॥ १.१.५ ॥

Earth, Water, Fire, Air, Ether, Time, Space, Self, and Mind (are) the only Substances.

All द्रव्य are eternal. Earth, Water, Fire, Air are physical realities while the rest are non-physical realities. Note that आकाश is not the gross space, but it is simply a postulated द्रव्य to which sound inheres as it cannot inhere to any other द्रव्य. The physical realities are made of परमाणु - not perceivable physical smallest indivisible particles. The mind is made of अणु - not perceivable non-physical minute entity. The realities of Self, Time, Space and Ether are not made of entities and are all-pervasive (विभु). 

2. गुण - Qualities inherent in द्रव्य - i.e. द्रव्य is its substratum. गुण is enumerated in Vaisheshika-sutra: 

रुपरसगन्धस्पर्शाः संख्याः परिमाणानि पृथक्त्वं संयोगविभागौ परत्वापरत्वे बुद्धयः सुखदुःखे इच्छाद्वेषौ प्रयत्नाश्च गुणाः ॥ १.१.६ ॥

रुप - form, रस - taste, गन्ध - smell, स्पर्शः - touch, संख्याः - numbers, परिमाणानि - measures, पृथक्त्वं - separateness, संयोग - conjunction, विभाग - disjunction, परत्व - priority, अपरत्व - posteriority, बुद्धि - intellect, सुख - happiness, दुःख - sorrow, इच्छा - desire, द्वेष - hatred, प्रयत्न - volitions

The later commentators added 7 more to this list to make it 24: weight, fluidity, viscosity, dispositional tendency, dharma, adharma, sound

All these are found in some or the other द्रव्य as its property. For example:

काल has परत्व - priority, अपरत्व - posteriority. 

आत्मा has बुद्धि - intellect, सुख - happiness, दुःख - sorrow, इच्छा - desire, द्वेष - hatred, प्रयत्न - volitions.

In common understanding, if red is the colour of an object, we tend to think that the red of this object is the same as the red colour of another object - because redness is not particular to the object. But गुण in Vaisheshika is not of that type, here it inheres to a particular द्रव्य, so the red of one द्रव्य is different from red of another द्रव्य. There is no universality of गुण across objects. That's why the word quality or property for गुण may be misleading.

3. कर्म is action that inheres to द्रव्य - i.e. it cannot be without a द्रव्य which is its substratum. 5 kinds are given in Vaisheshika-sutra:

उत्क्षेपणमवक्षेपणं आकुञ्चनं प्रसारणं गमनमिति कर्माणि ॥ १.१.७ ॥

उत्क्षेपणम् - throwing upward, अवक्षेपणम् - downward, आकुञ्चनम् - contraction, प्रसारणम् - expansion गमनम् - mobility

All these are found in some or the other द्रव्य as its property.

4. सामान्य - general, Universal properties shared across entities. How to determine the commonality or universality among the entities to group them together? All cows have cowness - how to define cowness? To define a thing, we must identify one unique thing which makes it distinct from all others. So is there a unique thing for cowness? This sometimes imperceptible common feature which groups all the similar individuals into a group is सामान्य or also called जाति.

The universal is always a धर्म - whose substratum is द्रव्य, गुण, कर्म. It is eternal - even if all cows are destroyed, cowness remains. 

5. विशेष - particular, Unique characteristics distinguishing one entity from another. This is opposite to सामान्य. One paramanu of earth is different from another paramanu of the same earth, i.e. विशेष which makes them to be different. Without this विशेष as a differentiating factor, there would have been no two paramanu to distinguish - but only one.

When we perceive a thing, both सामान्य (general family) and विशेष (specific individual) are perceived together. That’s how when we have the instance of experience of another individual of the same family again we are able to relate to the previous instance of experience which is of a different individual but the same class. So unless the experience of commonality of the general family was not there along with the experience of the individual before, this recalling would not happen.

6. समवाय - inherence, the essential relationship binding attributes or actions to their substratum, the whole to the parts, or universal to the particulars. This relationship is never separable, hence eternal, unlike the two गुण - संयोग -  conjunction, विभाग - disjunction which is temporary. Padartha, the categories of reality, are connected together through समवाय as धर्म-धर्मी. There are 5 समवाय relationships:

1. Dravya and guna

2. Karma and dravya

3. Saamaanya and vishesha

4. Anga and angi 

5. Visesa and nitya-dravya

7. अभाव - nonexistence, recognized absence of an entity - conspicuous. Sun in the night. This was added later to the list of 6 original padarthas.

Two kinds: 

1. संसर्गाभाव - absence of one thing in relation to another which is feasible - jar on the table. This is of three kinds:

   1. प्रागभाव - absence of house before its built, 

   2. प्रध्वम्साभाव - absence of pot after its broken, 

   3. अत्यन्ताभाव - absence of colour or shape for air

2. अन्योन्याभाव - absence of something in relation to another which is not even feasible - buffalo in a horse

2. Who Am I?

आत्मा in Nyaya-Vaisheshika doesn’t get that supreme status seen in Vedanta or other darshana. It is seen more as a necessity to support the ontological and epistemological framework that the system focuses upon.  

• Ontological Necessity - Vaisheshika posits it as a substratum of cognition, pleasure, pain, and memory. 

• Epistemological Necessity - Nyaya posits it as a knower for cognition through anumana rather than any direct experience.

Perception/cognition/knowledge, called बुद्धि in nyaya-vaisheshika, is a quality (गुण), to which there must be a धर्मी, substratum, it must inhere to - this is postulated as the entity Self. Self is not a conscious entity in Vaisheshika as postulated in other darshanas, but it is simply a substratum for cognition and other attributes as given by Nyaya-sutra:

इच्छाद्वेषप्रयत्नसुखदुःखज्ञानानि आत्मनः लिङ्गम् इति। Desire, aversion, volition, pleasure, pain and knowledge are the marks (linga) of Atma.

Vaisheshika-sutra adds to that list a few more attributes or actions:

प्राणापाननिमेषोन्मेषजीवनमनोगतीन्द्रियान्तर विकाराः सुखदुःखेच्छाद्वेष प्रयत्नाश्चात्मनो लिङ्गानि ॥ ३.२.४ ॥. The ascending life-breath, the descending life-breath, the closing of the eye-lids, the opening of the eye-lids, life, the movement of the Mind, and the affections of the other senses.

Thus Nyaya-sutra states only the attributes while vaisheshika-sutra add action also to it to complete the definition of the Self as a drvaya that has both action and attribute.

Each individual being (jīva) has its own distinct Self. Since these mental states differ in each person and are not shared, the plurality of selves is inferred. The Self is all-pervasive and eternal.

3. How do we know reality?

There are 4 accepted pramana by Nyaya and Vaisheshika:

• Pratyaksha - direct perception through sense organs via mind, experiences by mind alone such as joy and sorrow. It is defined as knowledge that arises from the contact of sense organs with sense objects.

• Anumana - inference arrived through syllogism, a type of deductive reasoning based on premises and logical argument. It literally means knowledge/cognition (mana) arrived at following (anu) another knowledge/cognition. Smoke is seen, the unseen fire is concluded to be present. 

There are five elements for syllogism (avayava)

• Pratijñā (प्रतिज्ञा) – Proposition (e.g., The hill has fire.). Fire is sadhya, not directly perceivable, but whose presence is to be proved or inferred

• Hetu (हेतु) – Reason (Because there is smoke.) this is also linga - the indicator

• Udāharaṇa (उदाहरण) – Example (Wherever there is smoke, there is fire—like in the kitchen.)

• Upanaya (उपनय) – Application (There is smoke on the hill.)

• Nigamana (निगमन) – Conclusion (Therefore, the hill has fire.)

There must be an invariable concomitance - vyapti - between sadhya and linga/hetu. 

व्याप्तिः = "अन्यतराभावे अन्यत्राभावः"

“When the absence of one implies the absence of the other”

This vyapti has been arrived at through what is called as अन्वय-व्यतिरेक.

• Anvaya (अन्वय) – Positive concomitance

Definition: When two things are always present together.

Logic: Yatra yatra dhūmaḥ, tatra tatra vahniḥ – Wherever there is smoke, there is fire.

Use: Confirms that presence of hetu (smoke) indicates presence of sādhya (fire).

Pattern: If A (smoke), then B (fire).

• Vyatireka (व्यतिरेक) – Negative concomitance

Definition: When one is absent, the other is also absent.

Logic: Yatra yatra vahniḥ nāsti, tatra tatra dhūmaḥ nāsti – Wherever there is no fire, there is no smoke.

Use: Confirms that absence of sādhya (fire) means absence of hetu (smoke).

Pattern: If not B (fire), then not A (smoke).

This anumana is valid, as long as vyapti holds and logical argument is sound.

• Upamana - knowledge arrived at through comparison or analogy based on perception and verbal testimony. 

• Shabda - verbal testimony, usually of a trustworthy person. The topics could be drstartha - perceptible objects or adrsthartha - like God, soul, etc. Since sabda is based on words, Nyaya also focuses on having a logical structure to a sentence also. A valid logical sentence must conform to these 4 aspects:

  • Akanksha - expectancy

  • Yogyata - mutual fitness, absence of contradiction

  • Sannidhi - suitable proximity between different words

  • Tatparya - intended meaning

4. What is mind?

मन is one of the 9 द्रव्य and hence it is a पदार्थ. The mind is made of अणु - not perceivable non-physical minute entity. It is limited/finite unlike the Self, but eternal as द्रव्य. The role of manas is the mediator between the sense-organs and the Self. Nyaya-sutra states: युगपत्ज्ञानानुत्पत्तिः मनसः लिङ्गम् ।। १६ ।। - The characteristic of mind is that it removes the possibility of having more than one perception at a time among all the available perceptions. Even in a composite experience involving all sense-objects, there is only perception of one sense object at a time, but the quick succession of change of objects gives an impression of simultaneity of perception of all objects. It is therefore said to be atomic in composition (anu). It is not all pervasive because if it were so, then one must be able to experience all at the same time. As soon as the sense organ is in contact with the sense object, manas gets attached to it in no time. It is eternal because the Self is eternal and it continues to play the role of mediator in perception of objects through organs for ever for the Self.

Buddhi is simply the cognition or knowledge that arises when self-manas-sense organ-sense-object interaction is complete. As cognition or knowledge, buddhi is therefore an attribute or गुण of Self, but not an independent faculty as seen in other darshanas. It is also one of the 12 objects of knowledge that one must have in Nyaya. The outward object is conceived to make an impression on the Self as buddhi just as the seal on the wax. Nyaya-Vaisheshika doesn’t get into any discussion about explaining how a contact between sense organ and sense object converts into a psychical state. But in all this buddhi, the perception, the mediator mind is assumed between the Self and sense-organ. Buddhi can therefore be अप्रमा - invalid knowledge or प्रमा - right knowledge.

As opposed to later darshanas which had citta and ahankara listed as separate faculties of mind, there is no mention of these two in the nyaya-vaisheshika system. Remembrance due to past impressions and the desires that may arise consequently are all inhered to the Self itself. The notion of ahankara as the doer, experiencer etc. are also attributed to the Self.

5. What is the perfect state of happiness that I can achieve?

Liberation in Nyaya: In nyaya, liberation - निःश्रेयस, the highest good, is attained when there is full knowledge of these 16 categories.

1. pramāṇa (The instruments of valid knowledge),

2. prameya (The objects of valid knowledge),

3. saṃśaya (Doubt),

4. prayojana (Motive),

5. dṛṣṭānta (An example),

6. siddhānta (A tenet),

7. avayava (5 members of syllogism) - A syllogism is a logical argument made up of a set of premises that lead to a conclusion. It is a form of deductive reasoning, where if the premises are true and the logic is valid, the conclusion must also be true.

8. tarka (Hypothetical reasoning),

9. nirṇaya (Ascertainment),

10. vāda (Discussion),

11. jalpa (Wrangle),

12. vitaṅdā (Cavil),

13. hetvābhāsa (Faulty reasons),

14. chala (Quibble),

15. jāti (Futility) and

16. nigrahasthāna (Ground of defeat).

The first 8 and 10th are directly used in logical reasoning to arrive at the 9th - nirnaya. The rest, from 11th to 16th are more a manner of debate and strategy, but not direct constructive reasoning itself. 

The 4 pramana has been described before, and the 12 objects of knowledge - prameya as given by Nyaya-sutra:

आत्मशरीरेन्द्रियार्थबुद्ध्यवस्थादोषप्रेत्यभावफलदुःखापवर्गास्तु प्रमेयम्। (Nyāya Sūtra 1.1.9)

1. Ātma - Desire, aversion, volition, pleasure, pain and intelligence are the marks (linga) of Atma.

2. Śarīra (Body) - Body is the site of gesture, senses and sentiments.

3. Indriya (Senses) - Nose, tongue, eye, skin and ear are the senses produced from elements.

4. Artha (Object of the senses) - Smell, taste, colour, touch and sound are objects of the senses and qualities of the earth.

5. Buddhi (Intellect) - Intellect, apprehension and knowledge there are no different from one another.

6. Mana (Mind) - The mark of the mind is that there do not arise (in the soul) more acts of knowledge than one at a time.

7. Pravṛti (Activity) - Activity is that which makes the voice, mind and body begin their action.

8. Doṣa (Faults) - Faults have the characteristic of causing activity.

9. Pretyabhāva (Transmigration) - Transmigration means rebirth.

10. Phala (Fruit) - Fruit is the thing produced by activity and faults.

11. Duhkha (Pain) - Pain has the characteristic of causing uneasiness.

12. Apavarga (Release) - Release is the absolute deliverance from pain.

Using pramana and prameya, along with other supportive features of logical reasoning given in 16 categories, one gets the right knowledge - pramā - to attain the final object of knowledge, liberation - apavarga - overcoming other objects of knowledge that are obstacles: Nyaya-sutra 1.1.2:

दुःखजन्मप्रवृत्तिदोषमिथ्याज्ञानानामुत्तरोत्तरापाये तदनन्तरापायादपवर्गः। 

Liberation (apavarga) is the result of the sequential cessation of false knowledge, then faults, then activity, then birth, and finally suffering—each one ceasing as its immediate cause ceases. Cessation of suffering is liberation - apavarga.

Note all those obstacles are among the 12 objects of knowledge, prameya, listed earlier.

The Nyāya system includes doubt (saṃśaya) as well as error (viparyaya) and hypothetical reasoning (tarka) under apramā or invalid knowledge. 

Liberation in Vaisheshika: Vaisheshika-sutra states liberation as:

धर्मविशेष प्रसूतात् द्रव्यगुणकर्मसामान्य विशेषसमवायानां पदार्थानां साधर्म्यवैधर्म्याभ्यां तत्त्वज्ञानान्निःश्रेयसम् ॥ १.१.४ ॥

Liberation (niḥśreyasa) is attained through true knowledge (tattva-jñāna) of the six categories (padārthas)—substance, quality, action, generality, particularity, and inherence—originating from specific dharma, and realized through the methods of similarity (sādharmya) and dissimilarity (vaidharmya).”

According to the Vaiśeṣika system, invalid knowledge is of four kinds, viz., doubt (saṃśaya), error (viparyaya), indefinite perception (anadhyavasāya) and dream (svapna).

So both Nyaya and Vaisheshika state liberation ensues from right knowledge - while nyaya talks about it from a more epistemological perspective, vaisheshika takes it from an ontological perspective. There is not much glorification of this liberation as seen in the later darshanas - the Self which had incorrect knowledge through perception of objects will continue to have the perception of objects with correct knowledge thereby having no pain after liberation. So the bliss is presented in a rather understated negative way of simply having no pain.

6. The role of mind in liberation

Mind is simply an intermediary between the sense organ and the self to create perception which is the primary pramana. And other than that role to give right knowledge about the objects of knowledge which leads to liberation, there is nothing else explicitly mentioned about the mind’s role in liberation in sutras. In Nyaya-bhashya, there is however a description of doshas - raga, dvesha and moha. And so to remove these, some purification of mind is required although there are no explicit practices mentioned to do the same.

Theory of causation

Nyaya-Vaisheshika system espouses असत्कार्यवाद as causation - the effect is not pre-existent in the cause, but it is a distinct entity that comes into existence through the process of causation. This असत्कार्यवाद is also known as आरम्भवाद and it is different from सत्कार्यवाद proposed by Sankhya-Yoga schools which holds that the effect pre-exists in the cause in nascent form. Nyaya-Vaisheshika argue against सत्कार्यवाद as follows:

• If the effect were already in the cause, no transformation would be necessary.

• If a cause already contains the effect, the effect should be perceptible beforehand.

Conclusion

Nyāya-Vaiśeṣika plays a foundational role in Indian philosophical thought, addressing key aspects of ontology, epistemology, soteriology, and psychology. While other darśanas may appear more extensive and sophisticated, Nyāya-Vaiśeṣika remains critical for several reasons:

1. Nyāya systematically developed the science of logic and analytical reasoning, establishing a structured framework for debate and philosophical discourse. This methodology is so fundamental that followers of all darśanas study Nyāya not only to properly understand their own school of thought but also to engage in formal debates and disputations with other philosophical traditions. Because of its logical rigor, Nyāya serves as the intellectual foundation for critical reasoning, making it indispensable for dialogue between various darshanas for their comparative studies.

2. In the realm of epistemology, Nyāya’s emphasis on the method of inference (*anumāna*) is to such a degree that other darśanas incorporated it into their respective systems as a valid *pramāṇa* (means of knowledge). This contribution significantly shaped Indian philosophical inquiry, making inference a central aspect of knowledge acquisition across various schools.

3. Vaiśeṣika, through pure logical reasoning in the absence of observational tools, conceptualized an indivisible minute entity known as paramāṇu, which serves as the building block for all physical entities. Remarkably, this idea aligns closely with the modern atomic theory, demonstrating the depth of Indian philosophical speculation on the nature of matter. Vaiśeṣika is one of the earliest philosophical systems that leaned toward materialism, emphasizing the categorization of reality through physical substances. However, it does not restrict itself solely to materialism, as it also acknowledges the existence of abstract entities such as qualities (guṇa), actions (karma), and inherence (samavāya) - thus it is a more comprehensive realism rather than pure materialism.

4. The pluralistic realism proposed by Vaiśeṣika marked the first systematic ontological framework in Indian thought. By affirming that external reality possesses an independent existence, it countered the idealist tendencies of certain *nāstika* darśanas, such as the Buddhist *Vijñānavāda*, which contended that reality is merely a mental construct. This philosophical stance helped prevent the unchecked spread of extreme idealism, maintaining diversity in Indian philosophical inquiry and fostering the development of more inclusive darśanas.

Although later schools expanded on these foundational ideas, Nyāya-Vaiśeṣika provided the intellectual groundwork upon which a lot of Indian thought was built. Its contributions to logic, epistemology, and ontology ensured that all subsequent darśanas integrated its methodologies, making it an indispensable pillar of Indian philosophy.

Sankhya & Yoga

Although Sāṅkhya is as ancient as the Vaiśeṣika darśana—if not older—its full philosophical scope became more functionally integrated and spiritually compelling when it transitioned from a mere system of speculative knowledge to an experiential path, as assimilated by the Yoga darśana. This synthesis of Sāṅkhya and Yoga created a composite system that was not only logically coherent but also practically transformative, offering a more comprehensive philosophical package than even the Nyāya–Vaiśeṣika combination, for several reasons:

1. First, the atomistic pluralism of Nyāya–Vaiśeṣika, though logically robust, lacked the conviction born of direct experience. In contrast, Sāṅkhya–Yoga provided a streamlined, introspective, and practice-based approach that grounded its metaphysics in the transformative experience of meditation and discipline.

2. Second, while Nyāya–Vaiśeṣika upheld an objective realism, the worldview of Sanātana Dharma required a counterbalance to that stance—especially one rooted within its own orthodox framework (apart from the Buddhist critique). Sāṅkhya offered that alternative, positioning itself between strict realism and idealism by acknowledging both an objective material cause (prakṛti) and a transcendent subjective observer (puruṣa).

3. Third, the plurality of independent realities asserted by Nyāya–Vaiśeṣika appeared somewhat fragmented or ad hoc, especially when compared to the elegant dualism of Sāṅkhya. The latter's metaphysical simplicity—dividing reality into just two eternal principles—puruṣa and prakṛti—was not only conceptually parsimonious but also existentially meaningful, as it directly addressed the nature of bondage and liberation. Moreover, this dualism was firmly rooted in yogic experience, making it more accessible and spiritually engaging.

4. Lastly, Sāṅkhya seamlessly integrates psychology and cosmology, presenting a unified metaphysical vision where the individual mind and the external universe are built from the same tattvas, follow the same laws, and evolve from the same primal root, prakṛti. The puruṣa is the conscious witness of both microcosm and macrocosm that are fundamentally built by the same tattvas whose primordial cause is Prakriti.

Theory of causation

Sankhya simplifies the doctrine of pluralistic reality held on to by Vaisheshika-Nyaya to a dualistic one in this way. The central premise for Sankhya is सत्कार्यवाद as causation - an effect is pre-existent in its cause in a latent form unlike the Vaisheshika-Nyaya which considers the effect to be distinct and produced new from the cause. This सत्कार्यवाद is also known as परिणामवाद. The reasons for सत्कार्यवाद is given in Sankhya-karika:

असदकरणादुपादानग्रहणात्, सर्वसम्भवाभावात्।

शक्तस्य शक्यकरणात्, कारणभावाच्च, सत्कार्यम् ॥९॥

1. Asadakaranāt - This principle states that something that does not exist cannot be created or brought into existence. Therefore, if the effect did not pre-exist in the cause, it would be a new creation from nothing, which is considered impossible.

2. Upādāna grahaṇāt - Every effect needs a specific material cause to be produced. For instance, a pot is made from clay, and a cloth is made from threads. This implies that the effect, in its potential form, is already present within the material cause, waiting to be manifested.

3. Sarvasambhavābhāvāt - Not all effects can be produced from all causes. A pot cannot be made from milk, nor can a cloth be made from sand. This limited relationship between causes and effects suggests that the specific potential for each effect already exists within its appropriate cause.

4. Śaktasya Śakyakaraṇāt - A cause possesses a specific capacity or power to produce a particular effect. This power is not a new acquisition but a pre-existing potential within the cause. If the effect did not pre-exist in the cause, the cause would be devoid of any capacity to produce it.

5. Kāraṇabhāvāt - The effect is not a separate entity created from the cause; instead, it is a transformation or manifestation of the cause. This inherent connection between cause and effect underscores the pre-existence of the effect within the cause.

1. What is the criterion for reality and what it is?

The criterion for reality in the Sāṅkhya-Yoga system, though not explicitly stated in any single scripture, can be inferred from its foundational texts as follows:

1. Uncreated – Reality does not arise from nothing; it must pre-exist in some latent form.

2. Eternal – True reality is beyond birth and destruction, existing timelessly.

3. Independent – Fundamental reality does not rely on external conditions for its existence.

Based on these criteria, all material entities must originate from an eternal, uncreated, independent material cause going by सत्कार्यवाद and for avoiding infinite regression. However, observation reveals that inert matter cannot function autonomously—it requires both a conscious principle, which enables material phenomena to operate, and an experiencer, who perceives and interacts with these inert entities. Since this conscious principle is non-material, it must also be uncreated, eternal, and independent, thereby establishing the necessity of two fundamental realities within the Sāṅkhya-Yoga framework.

Thus, Sāṅkhya-Yoga posits the necessity of two fundamental realities:

1. Prakṛti (Primordial Matter) – The unchanging substratum of all material transformations.

2. Puruṣa (Pure Consciousness) – The independent, eternal observer, distinct from material reality.

The logical necessity of these dual realities is further elaborated in the Sāṅkhya-Kārikā, which systematically presents the reasoning behind this philosophical framework.

Logical Necessity of Primordial material cause Prakriti

Based on सत्कार्यवाद of Sankhya-Yoga system, since every effect is pre-existing in the cause and the effect is nothing but a manifestation of the cause in another form, one must arrive at a causeless unitary material cause finally to avoid infinite regression of the cause-effect chain due to the following reasons as given in Sankhya-karika:

भेदानां परिमाणात्, समन्वयात्, शक्तितः प्रवृत्तेश्च ।

कारणकार्यविभागात्, अविभागाद्वैश्वरूप्यस्य ॥ १५ ॥

Because of the finitude of differences among things, their systematic coherence, their directed activity based on inherent power, the distinction between cause and effect, and the unity underlying diversity—there must exist an unmanifest cause (prakṛti) underlying all phenomena.

1. भेदानाम् परिमाणात् – due to the finite (limited) nature of differences (among things). The first point, bhedānāṁ parimāṇāt, refers to the fact that the diversity we see in the world—of forms, objects, functions—is not infinite or chaotic. The variations among things are finite and classifiable, implying that they are not random but structured. This bounded nature of differences suggests that such variations must be derived from a common source that has the potential to generate finite but organized multiplicity. That source is prakṛti.

2. समन्वयात् – due to systematic interrelation or consistency. The second phrase, samānvayāt, points to the observable interdependence and coherence in the natural world. Systems—biological, physical, psychological—exhibit harmonious functioning. The sense organs work in coordination with the mind; the seasons transition regularly; actions lead to predictable consequences. Such systematic order implies a foundational principle that governs all parts uniformly, which again necessitates a unified causal principle like prakṛti.

3. शक्तितः प्रवृत्तेः च – and due to activity being guided by specific power or capacity. Next, śaktitaḥ pravṛtteś ca emphasizes that all actions in the world occur due to specific capacities or potentials inherent in things. Fire burns, water flows, the intellect discriminates—not because of external imposition but due to intrinsic powers. This directedness of activity implies that these capacities must pre-exist in their source. If all entities act according to their natures, the cause must contain the potency (śakti) for those effects. Thus, prakṛti must be the repository of all potentialities.

4. कारण-कार्य-विभागात् – due to the distinction between cause and effect. The next phrase, kāraṇa–kārya–vibhāgāt, draws attention to the observable distinction between cause and effect. A pot is different in form and function from the clay it comes from, yet it cannot exist without clay. This distinction, yet dependence, illustrates that effects are transformations of a material cause, not new creations as in असत्कार्यवाद as porosed by Nyaya-Vasheshika. Hence, a root cause is necessary for every effect—prakṛti being that foundational cause of the universe.

5. अविभागाद्वैश्वरूप्यस्य – and due to the indivisible nature of the lordly (or controlling) principle. Lastly, avibhāgād vaiśvarūpysya refers to the unity underlying all diversity. Despite the differences, there is a fundamental continuity in nature. The same laws govern distant stars and local physics. Human emotions, animal instincts, and natural rhythms all show signs of being aspects of a unified substratum. This pervasive unity, known as vaiśvarūpya (all-formedness), supports the conclusion that an indivisible, unmanifest essence must underlie all multiplicity—again pointing to prakṛti.

What is Prakriti? It is the primordial material cause for all creation. It is eternal, infinite, and independent. It is imperceptible to senses and mind because it is the cause of them and an effect cannot comprehend its cause:

• Limited Manifestation – The effect is only a partial expression of the cause. The cause contains latent potential beyond what is manifested in the effect, making full comprehension impossible.

• Transformation – In Satkāryavāda (Sāṅkhya’s doctrine of causation), the effect pre-exists in the cause but undergoes transformation (pariṇāmavāda). However, the effect does not retain the original state of the cause, preventing complete understanding.

Hence Prakriti being incomprehensible is also known as avyakta - the unmanifest. 

One may incorrectly consider Prakriti to be pure materialism, but like Vaisheshika, it does confine itself to be the cause of only physical entities, but also a cause of non-physical entities.

Composition of Prakriti: The first manifestation of Prakriti, buddhi, is seen to have properties of pleasure, pain and confusion or calmness, activity and dullness - so Prakriti itself must have tendencies of this nature. These fundamental three tendencies are called guna which constitute Prakriti. As they are elements of Prakriti, they are imperceptible to senses and mind. The three gunas according to Sankhya-karika have these nature and purpose:

प्रीत्यप्रीतिविषादात्मकाः प्रकाशप्रवृत्तिनियमार्थाः।

अन्योऽन्याभिभवाश्रयजननमिथुनवृत्तयश्च गुणाः॥ १२॥

The three guṇas—Sattva, Rajas, and Tamas—are of the nature of pleasure, pain, and delusion. They serve the purpose of illumination, action, and restraint, and they interact by mutually dominating, supporting, producing, and cooperating with each other.

1. Sattva - it is the element which has potential for conscious manifestation or illumination causing pleasure

2. Rajas - it is the element which has potential for activity causing suffering

3. Tamas - it is the element that has the potential to resist activity leading to ignorance and dullness.

The gunas are always in constant flux as seen in the mind where its effects of pleasure, pain and confusion are seen. All entities are constituted of these three gunas and the variety in creation is only due to differences in the composition of these gunas that make up the entities.

Logical Necessity of Pure Consciousness Purusha

But only a material cause which is inert can alone not give rise to this entire creation, a conscious principle is also needed to facilitate creation as given in Sankya-karika:

संघातपरार्थत्वात् त्रिगुणादिविपर्ययादधिष्ठानात् ।

पुरुषोऽस्ति भोक्तृभावात् कैवल्यार्थं प्रवृत्तेश्च ॥ १७ ॥

1. संघातपरार्थत्वात् - First, the body, senses, and mind—being composites—are not self-justifying; they do not exist for their own sake. Like a tool, they are structured in such a way that their purpose is clearly to serve something else. This “something else” is the puruṣa—the conscious principle that uses these instruments for experience. 

2. त्रिगुणादिविपर्ययात् - Second, the three guṇas—sattva, rajas, and tamas—constantly interact and oppose each other. Sattva illuminates, rajas agitates, and tamas obscures. These forces pull in different directions, creating inner conflict and change. For these oppositional tendencies to be coordinated and known, a non-changing observer must exist—an unchanging awareness that is not itself caught in the flux. That is puruṣa.

3. अधिष्ठानात् - Third, all cognition and experience require a stable support or substratum. Just as a screen supports a movie or a mirror reflects images, a constant background is needed to hold the changing mental and sensory phenomena. This stable foundation is not prakṛti, which changes, but puruṣa, which remains the same and enables experience.

4. भोक्तृभावात् - Fourth, we all feel the sense of “I am experiencing this,” “I am happy,” “I suffer”—this is the sense of being the subject or enjoyer (bhoktṛ). This subjective experience cannot belong to prakṛti or the mind, which are unconscious and inert. Hence, the existence of conscious puruṣa is necessary to account for lived experience.

5. कैवल्यार्थं प्रवृत्तेः - Finally, all human activity, whether material or spiritual, ultimately aims at some form of fulfillment or liberation—freedom from pain, bondage, or limitation. This liberation (kaivalya) is not for the body or mind, which are instruments, but for the conscious self that mistakenly identifies with them. Since liberation must belong to a real experiencer, distinct from prakṛti, puruṣa must be accepted as a real, independent entity.

  Logical Necessity of Plurality of Purusha

Sankhya admits plurality of Purusa - each living being has an independent Purusa, eternal and infinite. Sankhya-karika states:

जननमरणकरणानां प्रतिनियमादयुगपत्प्रवृत्तेश्च ।

पुरुषबहुत्वं सिद्धं त्रिगुण्यविपर्ययाच्चैव ॥१८ ॥

The multiplicity of souls (purusha) is established since birth, death and the instruments of cognition and action are allotted severally; from the non-simultaneity of activities; and from the diverse modifications due to the three gunas.

•  जननमरणकरणानां प्रतिनियमात्

"Because birth, death, and instruments (karaṇas) are individually regulated"

This means that each body is born, grows, and dies at different times. The senses, mind, and physical functions vary from person to person. If there were only one puruṣa, then all bodies should have the same experiences, lifespans, or actions, but we see that each being operates independently. Thus, there must be individual puruṣas for each individual experience stream.

• अयुगपद् प्रवृत्तेः च

"Because actions do not occur simultaneously (in a shared stream)"

If there were only one puruṣa experiencing all actions, all bodies would function simultaneously as one unit of experience. But in reality, people act, feel, and think at different times. A person may be sleeping while another is eating. This asynchronous activity across beings shows that each one has a distinct consciousness.

• त्रिगुण्यविपर्ययात् च एव

“And also because of variation in the guṇic constitution"

Each person displays a different balance of sattva, rajas, and tamas. If puruṣa were one, there would be no reason for differences in personality, mental clarity, energy, or inertia across people. While the guṇas belong to prakṛti, their experiential reflection must vary only if the puruṣas are distinct, each witnessing their own evolving prakṛti.

पुरुषबहुत्वं सिद्धम् - "Therefore, the plurality of puruṣas is established". From these observations—independent birth-death cycles and non-simultaneous actions—it logically follows that there are many puruṣas, not one all-pervading conscious entity.

Here’s a concise table highlighting the differences between Puruṣa (Consciousness) and Prakṛti (Nature) in Sāṅkhya philosophy: