Historical revolution of journalism ethics
1. First stage: 16th and 17th centuries - emergence of ethical discourse in Western Europe
2. Second stage: 18th century - press controls weakened, journalists espoused a "public ethic"
3. Third stage: 19th century - evolution of the public ethic into an explicit liberal theory of the press
4. Fourth stage: 20th century - development and criticism of the liberal model
5. Fifth stage: Mixed media - increasing numbers of non-professional citizen journalists and bloggers engaging in journalism