Lokayata a philosophical concept. In the history of Indian philosophy, 'Lokayata Philosophy' implies 'popular philosophy' or 'philosophy of the common man' or 'worldly philosophy'. Haraprasad Shastri has explained that whatever has spread in concept among the general people may be called 'lokayata'. Such conceptualization of the term has been supported by pundits like Surendranath Dasgupta and Sarvapalli Radhakrishnan. Ancient spiritualists of Indian philosophy, especially Sankaracharya, Madhabacharya, Gunratna and others have also supported this view. Very recently, Debiprasad Bhattacharya has judged and evaluated lokayata philosophy in the light of Marxism. According to him, lokayata is not merely a philosophy present among the common people. 'Worldliness' is its principal element, 'soul beyond body' and the 'afterlife' are mere imaginations and life's goal means material achievement and desire. The adherents of Carvaka in ancient Indian philosophy supported this view and claimed themselves as lokayata. Lokayata thus implies the philosophy of the general masses, a materialistic philosophy, and also Carvaka philosophy.

There are differences of opinion regarding the time of origin of lokayata philosophy. But most people agree that its genesis happened during epic era, that is, between 6th century and 2nd century BC. Some, however, trace it to 2nd or 3rd century AD, which followed the eras of Jainism and Buddhism. Although there may be differences of opinion regarding its genesis, Brihaspati is considered to be the original exponent of lokayata philosophy. For this reason, some even call it 'Barhaspatya Philosophy'.

No main book could be found till now on the subject of lokayata philosophy. The pundits cite its possible extinction as the cause. In their opinion, some comments on the lokayata or materialistic philosophy can be seen in the ramayana, mahabharata and the books on jainism and buddhism. Again, some philosophic communities have tried to counter this contention by accepting the lokayata philosophy as something which preceded (purba-paksha) these. Therefore, some people also term lokayata philosophy the philosophy of 'purba-paksha'.'

A book titled Tattvopaplavasimha written by Jayarashi Bhatta and edited by Sukhlalji and Parikh was published by the Baroda Oriental Institute of India in 1940. This book created a great stir among the intellectual circle and above all people like Sarvapalli Radhakrishnan and Dakshinaranjan Shastri accepted the book as the only surviving book on lokayata philosophy. According to them, this book has described in detail the materialistic strands of lokayata philosophy. But many including Debiprasad Chattopaddhyai opposed this view and said that the main contents of the book were 'imaginary' and it displayed a 'tendency' towards dogmatism. '...Tattvopaplavasimha mentions about the futility of materialism at the very outset. But experts on Indian philosophy like Kamal Shil, Jayanta Bhatta, Goonratna and Madhab Acharya have depicted lokayata philosophy as materialism.'

Dakkhinaranjan Shastri mentions about three communities of lokayata philosophy: 'Baitandik community, 'Dhoorta' community and 'Sushiksita' community. The philosophical theory of lokayata philosophers is founded on their theory of knowledge. According to them, direct observation is the only proof; no conjecture can be accepted as proof, and words are not proof of anything; words of 'Veda' or 'Sruti' are not reliable for them under any circumstances. All knowledge and ideas are created from exposures of the senses. Lokayata philosophy is therefore experiential and materialistic. According to them, the direct element is the mind, what are received through the five senses are indirect feelings. Therefore, the direct element is the main proof for all proofs.

The metaphysics of the lokayata philosophers has been built on their theory of knowledge or experience. They reject all kinds of spiritualism and provide materialistic explanations to external problems. They are therefore very critical of spiritualism. Anything beyond observation, such as God, soul, paradise, hell and after-life cannot be accepted, and matter is the only truth. Against the theory of five elements of Indian philosophy, viz. sky, air, fire, earth and water, they put forward the doctrine of four elements. According to them, the main elements are: air, fire, earth and water; these elements attain their distinct qualities through a natural process and the world has been created in a normal course from these four matters. The world is not, therefore, a creation of God.

The lokayata philosphers are also known as 'Dehatmabadi' or 'Bhuchaitanyabadi'. They do not recognize the existence of any extra-physical soul. According to them, the body having consciousness is the soul; there is no separate soul, consciousness is a property of an individual physique; soul is not the quality of any spiritual entity. An individual physique is composed of the four material elements. They gave rise to the body by mixing in certain proportions; that body also gives rise to a new quality called consciousness. Therefore, consciousness emerges from the physical body; it is born centering on the body itself.

Lokayata philosophy accepted money and desire as the ultimate purpose of life instead of 'dharma' and 'moksha'. 'Pleasure' means 'bodily pleasure'. If there is no extra-physical soul (atman), and if body is the only truth, then there cannot be anything called atmik (soul-based) happiness. Therefore, seeking physical pleasure and happiness is the only goal of human life. The moral view of lokayata philosophers is that, as long as humans are alive, they should strive for pleasure and happiness; if needed, loans may be made for buying butter. [Pradip Kumar Ray]