Kapeliush Fedor (1876–1945) – writer, journalist, translator, historian of religion, author of articles and booklets on political history. He translated works by K. Marx and K, Kautsky from German. In the Soviet religious history he left two inputs: his books ‘Religion of Early Capitalism’ and ‘Economics and Religion’, where he analyzed a concept of interrelations of economics and religion. According Marxist social and economical theory, he argued that in the epoch of early capitalism there was a specific religious ideology as a supplement to the economical basis. He criticized leading Western theoretical thinkers in the field of sociology of religion from Marxist positions – he knew their works quite well. Particularly, he was critical to the theory by M. Weber and W. Sombart, who wrote that Calvinism was an important term of shaping capitalism; K. offered to turn that theory out and pout economics in the basis and to explain ascetic views of Calvinists with the conditions of initial accumulation of capital and growing industry.