However, Seeley declined to publicly acknowledge his authorship of "Ecce Homo", which was only first officially stated in a posthumous edition that was published in 1895. His later essay on "Natural Religion", signed "by the Author of "Ecce Homo"," which denied that supernaturalism is essential to religion and maintained that the negations of science tend to purify rather than destroy Christianity, satisfied few and excited far less interest than his earlier work. In 1869, he was appointed professor of modern history at the University of Cambridge. He was a popular instructor and prepared his lectures carefully, which were well attended. In historical work, he is distinguished as a thinker rather than as a scholar. He valued history solely in its relation to politics, as the science of the state. He maintained that history should be studied scientifically and for a practical purpose, the solution of existing political questions. Thus, he naturally devoted himself mainly to recent history, especially to the relations between England and other states. His "Life and Times of Stein", a valuable narrative of the anti-Napoleonic revolt, led by Prussia mainly at Heinrich Friedrich Karl von und zum Stein's instigation, was written under German influence and shows little of the style of his short essays. Its length, its colourlessness, and the space it devotes to subsidiary matters render it unattractive. Far otherwise is it with his "The Expansion of England" (1883). Written in his best manner, that essay answers to his theory that history should be used for a practical purpose; it points out how and why Britain gained its colonies and India, the character of the British Empire and the light in which it should be regarded. As a historical essay, the book is a fine composition, and its defence of the empire was then very persuasive. His defence consists largely of the claim that British rule was in India's best interest. Seeley also questioned the usefulness of India to the power and security of Britain and even claimed that there was 'no doubt' that India vastly increased the responsibilities and dangers to Britain. The book contains this much-quoted statement: "we seem, as it were, to have conquered half the world in a fit of absence of mind". "Expansion of England" appeared at an opportune time and did much to make Englishmen regard the colonies not as mere appendages but as an expansion of the British state as well as of British nationality and remind them of the value of the empire in the East. The essay was reprinted ten times in the year in which it was published and many more times in later years.