Charvaka (IAST: Cārvāka), originally known as Lokāyata and Bṛhaspatya, is the ancient school of Indian materialism. Charvaka holds direct perception, empiricism, and conditional inference as proper sources of knowledge, embraces philosophical skepticism and rejects Vedas, Vedic ritualism and supernaturalism.
Ajita Kesakambali is credited as the forerunner of the Charvakas, while Brihaspati is usually referred to as the founder of Charvaka or Lokāyata philosophy. Much of the primary literature of Charvaka, the Barhaspatya sutras (ca. 600 BCE), are missing or lost. Its teachings have been compiled from historic secondary literature such as those found in the shastras, sutras and the Indian epic poetry as well as in the dialogues of Gautama Buddha and from Jain literature.
One of the widely studied principles of Charvaka philosophy was its rejection of inference as a means to establish valid, universal knowledge, and metaphysical truths. In other words, the Charvaka epistemology states that whenever one infers a truth from a set of observations or truths, one must acknowledge doubt; inferred knowledge is conditional.
Charvaka is categorized as a heterodox school of Indian philosophy. It is considered an example of atheistic schools in the Hindu tradition.