After Weber's immense productivity in the early 1890s, he did not publish any papers between early 1898 and late 1902, finally resigning his professorship in late 1903. Freed from those obligations, in that year he accepted a position as associate editor of the Archives for Social Science and Social Welfare,[11] where he worked with his colleagues Edgar Jaffé [de] and Werner Sombart.[6][12] His new interests would lie in more fundamental issues of social sciences; his works from this latter period are of primary interest to modern scholars.[7] In 1904, Weber began to publish some of his most seminal papers in this journal, notably his essay The Protestant Ethic and the Spirit of Capitalism, which became his most famous work[13] and laid the foundations for his later research on the impact of cultures and religions on the development of economic systems.[14] This essay was the only one of his works from that period that was published as a book during his lifetime. Some other of his works written in the first one and a half decades of the 20th century – published posthumously and dedicated primarily from the fields of sociology of religion, economic and legal sociology – are also recognised as among his most important intellectual contributions.[6]