materialism in ancient India, and to trace their evolution. While commenting on his work on Lokayata, German indologist Walter Ruben called him a "thought-reformer", who was "conscious of his great responsibility towards his people living in a period of struggle for national awakening and of world-wide fighting for the forces of materialism, progress, humanism and peace against imperialism. He has written this book Lokayata: A Study in Ancient Indian Materialism against the old fashioned conception that India was and is the land of dreamers and mystics". This study questioned the mainstream view that Indian philosophy's sole concern was the concept of Brahman. "From the scattered references in the ancient philosophical literature which were completely hostile to the ancient materialist schools, Debiprasad Chattopadhyaya reconstructed the philosophy of Lokayata, which consistently denied the existence of brahman and viewed pratyaksa (perception) as the sole means of knowledge. He demolished the so-called "interpretation of synthesis" which sought to combine the diverse philosophical traditions of India to form a ladder that leads to the philosophy of Advaita Vedanta. Being a Marxist, Chattopadhyaya's uses the method of historical materialism to study "the ultimate material basis of the primitive deha-vada and the primitive rituals related to it" and to reveal how these could "be connected with the mode of securing the material means of subsistence". He also traced "the course of development this archaic outlook eventually underwent". Indian Philosophy: A Popular Outline (1964) It was an introductory book that examined Indian philosophy through an interdisciplinary approach, drawing on anthropological, economic and philological studies. The book traced the philosophical development in India from the Vedic period to later Buddhism. In this introductory study, Debiprasad Chattopadhyaya targets another important myth that overshadows the study of Indian philosophy – that of the presupposed predominance of shastrartha or textual interpretation. He views the development of Indian philosophy as the consequence of real clashes of ideas – "contradiction constituted the moving force behind the Indian philosophical development". Dale Riepe in his review of this book says that Chattopadhyaya "combines the analytic sagacity of Hume with the impatient realism of Lenin". Indian Atheism: A Marxist Analysis (1969) This is yet another provocative critique of the standard accounts of Indian philosophy and religion. This book brings out a coherent historical account of atheism in India. In fact, according to Chattopadhyaya, "an unbiased survey of the Vedas clearly shows the total absence of religious consciousness