Ajita Kesakambali was an ancient Indian philosopher in the 6th century BC. He is considered to be the first known proponent of Indian materialism

Materialism

In philosophy, the theory of materialism holds that the only thing that exists is matter; that all things are composed of material and all phenomena are the result of material interactions. In other words, matter is the only substance...

. He was probably a contemporary of Buddha

Gautama Buddha

Siddhārtha Gautama was a spiritual teacher from the Indian subcontinent, on whose teachings Buddhism was founded. In most Buddhist traditions, he is regarded as the Supreme Buddha Siddhārtha Gautama (Sanskrit: सिद्धार्थ गौतम; Pali: Siddhattha Gotama) was a spiritual teacher from the Indian...

 and Mahavira

Mahavira

Mahāvīra is the name most commonly used to refer to the Indian sage Vardhamāna who established what are today considered to be the central tenets of Jainism. According to Jain tradition, he was the 24th and the last Tirthankara. In Tamil, he is referred to as Arukaṉ or Arukadevan...

. It has frequently been noted that the doctrines of the Lokayata school were considerably drawn from Ajita's teachings. Like those of Lokayatins, nothing survives of his teachings in script, except some scattered references made by his opponents for the sake of refutation. Thus, due to the nature of these references, the basic framework of Ajita's philosophy has to be derived by filtering out obscure legends associated with him. For instance, according to a Buddhist legend, he wore a blanket of human hair (Kesakambali in Sanskrit means "with the hair blanket"), "which is described as being the most miserable garment. It was cold in cold weather, and hot in the hot, foul smelling and uncouth".

Renowned historian DD Kosambi, who elsewhere calls Ajita a proto-materialist, notes that he "preached a thoroughgoing materialist doctrine: good deeds and charity gained a man nothing in the end. His body dissolved into the primary elements at death, no matter what he had or had not done. Nothing remained. Good and evil, charity and compassion were all irrelevant to a man's fate." According to an early Buddhist source, Ajita Kesakambali argued that:

There is no such thing as alms or sacrifice or offering. There is neither fruit nor result of good or evil deeds...A human being is built up of four elements. When he dies the earthly in him returns and relapses to the earth, the fluid to the water, the heat to the fire, the wind to the air, and his faculties pass into space. The four bearers, on the bier as a fifth, take his dead body away; till they reach the burning ground, men utter forth eulogies, but there his bones are bleached, and his offerings end in ashes. It is a doctrine of fools, this talk of gifts. It is an empty lie, mere idle talk, when men say there is profit herein. Fools and wise alike, on the dissolution of the body, are cut off, annihilated, and after death they are not.

According to Brahmajala Sutta

Brahmajala Sutta (Theravada)

The Brahmajala Sutta is the first of 34 suttas in the Digha Nikaya . The name comes from 'brahma' and 'jala'...

, Ajita propounded Ucchedavada (the Doctrine of Annihilation after death) and Tam-Jivam-tam-sariram-vada (the doctrine of identity of the soul and body), which denied the separate existence of eternal soul. The extent to which these doctrines, which were evidently inherited by Lokayata, were found contemptible and necessary to be refuted in the idealist

Idealism

In philosophy, idealism is the family of views which assert that reality, or reality as we can know it, is fundamentally mental, mentally constructed, or otherwise immaterial. Epistemologically, idealism manifests as a skepticism about the possibility of knowing any mind-independent thing...

, theist and religious literature of the time is a possible evidence of their popularity and, perhaps also, their philosophical sophistication.