Hindu philosophy is one of the oldest and most profound philosophical traditions in the world. It is traditionally classified into two broad categories: Āstika (orthodox) and Nāstika (heterodox) schools. The Āstika schools accept the authority of the Vedas and form the foundation of classical Hindu thought.

There are six primary Āstika schools, each offering a unique perspective on metaphysics, epistemology, and the path to liberation (moksha).

1. Nyāya: The School of Logic

Nyāya, founded by Sage Gautama, is the school of logic and epistemology. It emphasizes the process of valid reasoning and seeks to establish knowledge through systematic analysis. The school identifies four valid means of knowledge (pramānas):

• Perception (Pratyaksha): Direct sensory experience.

• Inference (Anumāna): Logical deduction based on observed patterns.

• Comparison (Upamāna): Knowledge gained through analogy.

• Testimony (Shabda): Trustworthy sources, such as the Vedas.

Nyāya philosophy is fundamental in Hindu thought, influencing other schools with its structured approach to knowledge and debate.

2. Vaiśesika: The School of Atomism

Developed by Sage Kanada, Vaiśesika is a school of natural philosophy that focuses on metaphysics and categorization. It proposes that the universe is composed of paramāṁus (indivisible atoms) and classifies reality into seven categories (padārthas):

1. Dravya (Substance)

2. Guṇa (Quality)

3. Karma (Action)

4. Sāmānya (Generality)

5. Viśeṣa (Particularity)

6. Samavāya (Inherence)

7. Abhāva (Absence)

Vaiśesika complements Nyāya by offering a systematic approach to physical reality and causation.

3. Sāṁkhya: The School of Dualism

Founded by Sage Kapila, Sāṁkhya is one of the oldest Hindu philosophical systems. It proposes a dualistic framework between Purusha (consciousness) and Prakriti (matter). Key concepts include:

• The 24 Tattvas (principles of existence), including intellect, mind, senses, and elements.

• Liberation (moksha) as the realization that Purusha is distinct from Prakriti.

• Rejection of a creator god, focusing instead on the interplay of natural forces.

Sāṁkhya deeply influenced later Hindu traditions, including Yoga and Vedanta.

4. Yoga: The Path to Self-Realization

Yoga, based on the teachings of Sage Patanjali’s Yoga Sutras, is a practical system for spiritual liberation. It shares philosophical roots with Sāṁkhya but introduces a structured path through the Eight Limbs of Yoga (Ashtanga Yoga):

1. Yama (Ethical disciplines)

2. Niyama (Self-discipline)

3. Asana (Physical postures)

4. Pranayama (Breath control)

5. Pratyahara (Withdrawal of senses)

6. Dharana (Concentration)

7. Dhyana (Meditation)

8. Samadhi (Enlightenment)

Yoga serves as a bridge between philosophy and practice, emphasizing meditation and self-discipline as a means to liberation.

5. Mīmāṁsā: The School of Ritual and Dharma

Mīmāṁsā, attributed to Sage Jaimini, focuses on Vedic interpretation and ritual practice. It argues that the Vedas are eternal and self-evident, and that fulfilling dharma (righteous duty) through rituals is the key to a prosperous life and spiritual progress. Key beliefs include:

• The eternity of the Vedas as a source of truth.

• Karma-kāṣṭa (ritualistic duties) as a means to attain worldly and spiritual benefits.

• Apūrva, a concept describing the unseen force generated by rituals, which leads to favorable outcomes.

Mīmāṁsā laid the groundwork for Hindu legal and ethical traditions.

6. Vedānta: The School of Ultimate Knowledge

Vedānta ("end of the Vedas") focuses on the philosophical teachings of the Upanishads, particularly the nature of Brahman (the ultimate reality) and Atman (the individual self). It has three major sub-schools:

• Advaita Vedānta (Non-Dualism, by Adi Shankaracharya): Asserts that Brahman and Atman are identical, and the world is an illusion (māyā).

• Vishishtadvaita Vedānta (Qualified Non-Dualism, by Ramanuja): Argues that the individual soul is distinct yet inseparable from Brahman.

• Dvaita Vedānta (Dualism, by Madhvacharya): Maintains that Brahman and Atman are eternally separate.

Vedānta is the most influential of the six schools, shaping modern Hindu thought and spiritual practices.

Conclusion

The six Āstika schools of Hindu philosophy represent a rich and diverse intellectual tradition. While each school has its unique approach, they collectively offer profound insights into logic, metaphysics, spirituality, and ethics.

Understanding these schools provides a deeper appreciation of Hindu thought and its influence on global philosophy and culture.