This book is about thinkers who have decisively contributed to the development of free speech philosophy. Although special emphasis is given here to the thought of John Milton and John Stuart Mill, traditionally regarded as the two towering figures who gave the idea of freedom of expression its classic shape, the text also discusses the contribution of many other thinkers. This list includes writers, journalists, lawyers, philosophers, politicians, and clergymen from Great Britain, continental Europe, and the United States.It is to be hoped that the text will prove useful for all readers interested in the issue of freedom of speech, inter alia students of political science, law, journalism, or mass communication. The book is the first of a series of texts on various aspects of freedom of expression that the Nicolaus Copernicus University Press in Toruń intends to publish in the near future. The second book of the series, by the same author, will appear under the title: Free Speech Defenders in Twentieth Century United States.