The ability of the Fourth Estate to accommodate a wide range of operational definitions may demonstrate the flexibility of the ideal, but it also ensures that the operation of the news media is based on a fundamental paradox. Of the institutions which emerged to provide checks and balances, to ensure that the political system was subject neither to the arbitrary authority of a capricious monarch, nor the tyranny of the majority, the press was the only one whose survival depended on, and was measured by, commercial success.

Commercial success helped to ensure independence, but also made the press' Fourth Estate ambitions vulnerable to owners seeking to inflate profit by tantalising audiences. Profit bought a ticket to independence. But it also held the seeds of the press' undoing as a political institution. While the press demanded and won the right to play a central role in the conduct of political life, its independence relied on the interest and goodwill of private owners. As Habermas observed, the transformation of the press into a commercial operation provided ‘the gate through which privileged private interests invaded the public sphere’ and newspaper publishers changed from being merchants of news to dealers in public opinion (Habermas, 1989: 182–5).

This transformation established the preconditions which made it possible for the widely varying definitions of the Fourth Estate, already outlined, to emerge and develop.