Pramana (Sanskrit: प्रमाण, Pramāṇa) literally means “proof” and “means of knowledge”

In Indian philosophies, pramana are the means which can lead to knowledge, and serve as one of the core concepts in Indian epistemology

It has been one of the key, much debated fields of study in Hinduism, Buddhism and Jainism since ancient times

It is a theory of knowledge, and encompasses one or more reliable and valid means by which human beings gain accurate, true knowledge

The focus of pramana is how correct knowledge can be acquired, how one knows, how one does not know, and to what extent knowledge pertinent about someone or something can be acquired

While the number of pramanas varies widely from system to system, many ancient and medieval Indian texts identify six pramanas as correct means of accurate knowledge and to truths: Three central pramanas which are almost universally accepted, which are perception (Sanskrit pratyakṣa), inference (anumāna), and “word”, meaning the testimony of past or present reliable experts (Śabda); and more contentious ones, which are comparison and analogy (upamāna), postulation, derivation from circumstances (arthāpatti), and non-perception, negative/cognitive proof (anupalabdhi)

Each of these are further categorized in terms of conditionality, completeness, confidence and possibility of error, by each school of Indian philosophies

The various schools of Indian philosophies vary on how many of these six are epistemically reliable and valid means to knowledge

For example, the Carvaka school of the Śramaṇa tradition holds that only one (perception) is a reliable source of knowledge, Buddhism holds two (perception, inference) are valid means, Jainism holds three (perception, inference and testimony), while Mimamsa and Advaita Vedanta schools of Hinduism hold all six are useful and can be reliable means to knowledge

The various schools of Indian philosophy have debated whether one of the six forms of pramana can be derived from other, and the relative uniqueness of each

For example, Buddhism considers Buddha and other “valid persons”, “valid scriptures” and “valid minds” as indisputable, but that such testimony is a form of perception and inference pramanas

The science and study of pramanas is called Nyaya