Debiprasad Chattopadhyaya (19 November 1918 – 8 May 1993) was an Indian Marxist philosopher. He made contributions to the exploration of the materialist current in ancient Indian philosophy. He is known for Lokayata: A Study in Ancient Indian Materialism, which is his exposition of the philosophy of Lokayata. He is also known for work on history of science and scientific method in ancient India, especially his 1977 book Science and Society in Ancient India on the ancient physicians Charaka and Sushruta. He was awarded the Padma Bhushan, India's third highest civilian honour, posthumously, in 1998. Biography Debiprasad Chattopadhyaya was born on 19 November 1918 in Calcutta. His father was a supporter of India's freedom struggle. It was probably his influence that initiated Debiprasad to two major passions in his life – Indian philosophy and politics; he quickly progressed towards radical streams in both fields, developing a lifelong commitment to Marxism and communist movement. At a very early stage of his life Chattopadhyaya immersed himself in the left nationalist movement by joining the Association of Progressive Writers, which was formed in 1936. Debiprasad Chattopadhyaya obtained his academic training in philosophy in Calcutta, West Bengal under eminent philosophers like Sarvapalli Radhakrishnan and S. N. Dasgupta. After standing first in philosophy at University of Calcutta both in B.A. (1939) and M.A. (1942), he did his post-graduate research work under Prof S. N. Dasgupta. He taught philosophy at the City College of Calcutta for three decades. Subsequently, he was appointed a UGC Visiting Professor at the universities of Andhra Pradesh, Calcutta and Poona. He remained associated with the activities of the Indian Council of Historical Research (ICHR), Indian Council of Philosophical Research (ICPHR) and the National Institute of Science, Technology and Development Studies (NISTADS) of the Council of Scientific & Industrial Research (CSIR) under various capacities. His second wife was the renowned educationist and Tibetologist, Dr. Alaka Majumder Chattopadhyaya (1926–1998). Debiprasad Chattopadhyaya's work on materialism and scientific method led to his active interactions with the international community of philosophers, historians and Indologists. He collaborated with some of the outstanding western scholars of the 20th century, like Joseph Needham, George Thomson, Bongard Levin and Walter Ruben. He was fellow of the German and USSR Academies of Sciences. He died in Calcutta on 8 May 1993. Major works Lokayata: A Study in Ancient Indian Materialism (1959) In his writings, Debiprasad Chattopadhyaya aimed to illuminate science and