In 1894, the British sociologist Benjamin Kidd published Social Evolution, an influential book that summarised and evaluated the prevailing social theories at the end of the nineteenth century: Karl Marx's socialism and Herbert Spencer's social Darwinism. Both of these conflicting theories were based on Darwinian evolutionary theory. In this book, Kidd discusses the immense changes that applied science has brought to the world and the interconnectedness of everyone. The book's ten chapters include discussions of the conditions of human progress, the function of religious beliefs, and the organisation of the working classes. Kidd found flaws in both Karl Marx's and Herbert Spencer's vision of society's future and concluded that religion was essential for the evolution of society because it acts in the interest of generational group survival rather than individual competition. Social Evolution called for a comprehensive study of society because a new era in Western civilisation was beginning.