Immanuel Kant (1724–1804)

Kant was a German philosopher. Habermas argues that Kant’s philosophy of right and of history form the foundations of the 18th-century theory of the public sphere. He undertakes a detailed analysis of Kant's work in terms of publicity.

Georg Wilhelm Friedrich Hegel (1770–1831)

G.W.F. Hegel was a German philosopher and author of Phenomenology of Spirit and Philosophy of Right. For Habermas, Hegel views public opinion in a similar way to Kant, but his view of civil society emphasizes its discontinuity and confusion. Civil society for Hegel cannot provide the rational basis for private people to turn political authority (domination) into rational authority.

Karl Marx (1818–83)

Marx was a German political philosopher and social critic and the author of Das Kapital and The Communist Manifesto. Habermas analyses Marx as a theorist of the public sphere who both denounced the idea, and yet used it to reveal the problems with bourgeois society.

John Stuart Mill (1806–73)

Mill was an English philosopher who wrote On Liberty, Utilitarianism, and Principles of Political Economy. Habermas analyses Mill as a central theorist of the liberal public sphere. For Mill, public opinion is a powerful force, but one that needs to be controlled.

Jeremy Bentham (1748–1832)

Bentham was an English philosopher and the author of Fragment on Government and Introduction to the Principles of Morals and Legislation. Bentham is best known for formulating the principle of utility—all humans should maximize utility by producing the greatest happiness for the greatest number.

Alexis Charles Henri Clerel de Tocqueville (1805–1859)

Tocqueville was a French social theorist and the author of Democracy in America and L'Ancien Régime et la Révolution. Along with Mill, Tocqueville is identified by Habermas as an ambivalent liberal theorist of the public sphere.