Charvaka Philosophy is an atheistic, materialistic and hedonistic thought, named after Charu or Brhaspati, who is believed to have been the propounder of this system. The Rg Veda (X.72) identifies him with Laukya Brhaspati. Charvaka philosophy is called Lokayata, as it admits the existence of this world (loka) alone. Materialist philosophers, referred to as Charvakas, are also known as Lokayatas or Laukayatikas as they act like ordinary people (loka).
The Barhaspatya-sutras, also known as Lokayata-sutras, are no longer extant. However, Dakshinaranjan Shastri collected 54 sutras of Brhaspati which form the core of this philosophy. Sukhalalji Sanghavi is of the opinion that Tattvopaplavasingha by Jayarashi Bhatta is a work of the old Charvaka school. But others note that its extreme skepticism is not characteristic of the Charvaka school.
Information about Charvaka philosophy views may be gathered from the polemical deliberations of other schools. Apart from the account of Charvaka philosophy found in the Rg Veda, considerable material is also contained in the Chhandogya Upanisad (8. 7-9), the mahabharata (Shantiparva and Shalyaparva), Krishnamishra's Pravodhachandrodaya, Madhavacharya's famous Sarvadarshanasanggraha, Vatsyayana's Nyayabhasya (2.1.37; 3.2.35), Sridhara's Nyayakandali, Jayanta's Nyayamanjari, Udayana's Nyayakusumanjali (1.15), Prabhachandra's Nyayakumudachandra, Shankara's Sharirakabhasya (1.1.1; 2.2.2; 3.3. 53-54) and Vachaspati's Bhamati (3.3.53).
According to Charvaka philosophy, all knowledge is derived from the senses. Inference has no value and the scriptures are false. What cannot be seen does not exist. There are no other worlds as they cannot be perceived.
Charvakas believe that there are four elements (bhutachatustaya): earth, water, fire and air. Everything is composed of these four elements, and it is the combination of these elements which produces consciousness (chaitanya). Charvakas do not believe in abstract concepts such as vice and virtue, or in causal relationships. They believe that it is the 'essential nature' (svabhava) of a thing to undergo transformation by itself (svatah). Moderate (shiksita) Charvakas, however, argue that a thing comes into being due to its 'essential nature'. They admit the validity of perception and inference.
According to Charvaka philosophy, sensual pleasure is the only end of human beings. Charvakas do not believe in Hell as a separate state of being but only as earthly suffering. Liberation is the dissolution of the body. Death is the end of all. After death, the body and consciousness cease to exist (na pretya sangjnasti, Brhadaranyaka Upanisad 2.4.12). [Amarnath Bhattacharya]