calls Debiprasad's Lokayata "a work of originality and world significance...a fully-founded work showing the philosophical implications of historical considerations." Chattopadhyaya is a proponent of historical and dialectical materialism, writes Riepe, and Chattopadhyaya's book, according to Riepe, is a classic. Giving an overview of Debiprasad's other books Riepe writes, "These indications of the herculean efforts of Debiprasad are earnest tokens of his awareness of the great work still to be done for Indian philosophy. Although he has planted almost alone in the Indian fields, others are slowly harvesting the results at home and abroad where his renown is exceeding many of the leading idealists". According to Chattopadhyaya, states Riepe, "Buddha looked backwards to the tribal collectives and wanted to revive... the imaginary substance of the tribe...". According to Dale Riepe, "Chattopadhyaya claims most of the ancient Indian traditional philosophers were atheists", and contrasting the approach taken by Debiprasad with the approach taken by followers of modern Western idealism like S.N. Dasgupta, Riepe writes: The various publications of Chattopadhyaya on Carvaka/Lokayata have been praised as pioneering and important contributions to the studies by Ramakrishna Bhattacharya. However, Bhattacharya also questions Chattopadhyaya analysis. For example, Ramkrishna Bhattacharya states, "Chattopadhyaya did not deny Ajita Kesakambali was a materialist, but chose to emphasize that 'Ajita was no less a philosopher of futility and moral collapse than the Buddha, Mahavira, Purana and Pakudha [...]". Bhattacharya notes that "Chattopadhyaya brands Ajita's teachings as a philosophy of the graveyard". Chattopadhyaya's rational reconstruction of the history of Indian materialism in Lokayata: A Study in Ancient Indian Materialism and other texts, was one of the most significant contributions, states Rajendra Prasad. Chattopadhyaya's pursuit, notes Prasad, was "a result of much of his commitment to values of scholarship" as to the "communist movement" in India. His efforts to explain materialism and atheism in Indian philosophy in its antiquity, against the old fashioned conception that India was and is the land of dreamers and mystics, required "tremendous intellectual courage", yet "Chattopadhyaya never flinched in the face of isolation in his own profession". Endorsing the book Lokayata Joseph Needham wrote: "Your book will have a truly treasured place on my shelves. It is truly extraordinary that we should have approached ancient Chinese and ancient Indian civilisations with such similar results...." About Chattopadhayay's 1977 book, Science and Society in Ancient India, he said: "I feel that you have entirely proved your case that the Caraka-samhita