The Upanishads posit Brahman as the ultimate reality, the eternal and infinite principle from which all existence emanates.

Advaita Vedanta asserts that the individual self and the universal self are not separate entities, but rather two aspects of the same underlying reality.

The Nyaya-Vaisheshika school posits substance as the primary category of existence, defining it as that which exists independently and can serve as a substrate for qualities and actions.

The Samkhya school posits Purusha (consciousness) and Prakriti (matter) as the two fundamental principles that constitute reality.

The Yoga school posits Moksha (liberation) as the primary goal of spiritual practice, which involves the cessation of suffering and the realization of the true nature of the self.

Buddhist philosophy posits attachment as the root cause of suffering, emphasizing the need for detachment and non-attachment to overcome suffering.

Jain philosophy posits Moksha (liberation) as the primary goal of spiritual practice, which involves the shedding of karmic impurities and the realization of the true nature of the self.

Sikh philosophy posits Naam (divine name) as the central concept that guides spiritual practice, emphasizing the remembrance and repetition of the divine name as a means to connect with the divine.

Tantra philosophy emphasizes the manipulation and transformation of energy as a means to achieve spiritual liberation, often involving the use of mantras, yantras, and other ritual practices.

Kashmir Shaivism posits Shiva as the ultimate reality, representing the transcendent and immanent aspects of consciousness.

Advaita Vedanta emphasizes Jnana (knowledge) as the primary means to achieve spiritual liberation, involving the realization of the true nature of the self and its identity with Brahman.

Nyaya-Vaisheshika posits perception as the primary source of knowledge, emphasizing the direct and immediate apprehension of objects through the senses.

Samkhya posits Prakriti (matter) as the primary cause of the universe, which is composed of three fundamental qualities (gunas) that give rise to all phenomena.

Yoga emphasizes Samadhi (meditative absorption) as the primary goal of spiritual practice, involving the cessation of mental fluctuations and the realization of the true nature of the self.

Buddhism posits the Eightfold Path as the primary means to achieve Nirvana, involving right understanding, right thought, right speech, right action, right livelihood, right effort, right mindfulness, and right concentration.