Although classical liberals aspired to a minimum of state activity, they accepted the principle of government intervention in the economy from the early 19th century on, with passage of the Factory Acts. From around 1840 to 1860, "laissez-faire" advocates of the Manchester School and writers in "The Economist" were confident that their early victories would lead to a period of expanding economic and personal liberty and world peace, but would face reversals as government intervention and activity continued to expand from the 1850s. Jeremy Bentham and James Mill, although advocates of "laissez-faire", non-intervention in foreign affairs, and individual liberty, believed that social institutions could be rationally redesigned through the principles of utilitarianism. The Conservative Prime Minister Benjamin Disraeli rejected classical liberalism altogether and advocated Tory democracy. By the 1870s, Herbert Spencer and other classical liberals concluded that historical development was turning against them. By the First World War, the Liberal Party had largely abandoned classical liberal principles.