The book by German philosopher Max Stirner The Unique and Its Property has been described as the "most revolutionary ever written". First published in 1844, it constitutes a fierce polemic against left Hegelianism and its prominent representatives Ludwig Feuerbach, Bruno Bauer, Moses Hess, and others.

It is also a persistent and impressively written critique of both liberalism and socialism and communism, from the standpoint of an extreme and eccentric individualism. Karl Marx was one of the many contemporaries of Stirner who attempted to extensively refute his arguments.

More recently, Stirner has been variously characterized as a nihilistic anarchist, a precursor to Nietzsche, and a harbinger of existentialism.