The problem of knowledge in Indian philosophy encompasses various aspects, including the nature of knowledge, the sources of knowledge, and the criteria for valid knowledge.

The Nyaya school considers perception to be the primary source of knowledge, as it provides direct and immediate knowledge of objects.

In Indian philosophy, 'pramana' refers to the means or methods by which knowledge is acquired.

The Nyaya school recognizes perception, inference, and testimony as valid means of knowledge, but not comparison.

In Advaita Vedanta, Brahman is considered the ultimate source of all knowledge, as it is the eternal, unchanging reality from which everything else emanates.

Anatta, or non-self, is a central concept in Buddhist philosophy, which emphasizes the impermanence and interconnectedness of all phenomena.

In Indian philosophy, 'anupalabdhi' refers to the absence of perception, which is considered a means of establishing the non-existence of something.

The Mīmāṃsā school considers the Vedas, the sacred texts of Hinduism, to be the primary source of knowledge.

The Carvaka school is known for its materialistic philosophy, which emphasizes the primacy of physical reality and rejects the existence of anything beyond the material world.

In Indian philosophy, 'siddhanta' refers to an established conclusion or doctrine within a particular philosophical system.

The Vaiśeṣika school recognizes perception, inference, and testimony as valid means of knowledge, but not postulation.

In Jaina epistemology, kevala jnana, or perfect knowledge, is considered the primary source of knowledge.

The Sāṃkhya school emphasizes the distinction between purusha (consciousness) and prakṛti (matter), with purusha being the knower and prakṛti being the object of knowledge.

In Indian philosophy, 'tarka' refers to logical reasoning and argumentation, which is used to establish the validity of knowledge claims.

The Yoga school emphasizes the importance of meditation and concentration as means of acquiring knowledge and achieving self-realization.