The main aim of this thesis is to analyse and explore the philosophical justifications for freedom of speech during the nineteenth century and their application as political praxis. In this work, specific types of free speech argument are identified and examined in the light of the ideological stance of those who sought to argue for freedom of speech, primarily from key ideological perspectives of the nineteenth century, utilitarianism, liberalism and socialism. Initially three types of free speech argument are identified: the accountability argument, the liberty argument and the truth argument. However, on an inspection of socialist arguments for freedom of speech, the author suggests that a fourth sufficiently distinct type of free speech argument is present, particularly within the more mature works of socialist radicals and agitators. Though the arguments for freedom of speech overlap within different ideological and historical contexts, a case is made for a relatively distinct type of free speech argument within the socialist political praxis of free speech. Furthermore, in examining key political and philosophical texts, and an analysis of the free speech arguments in nineteenth century political pamphlets and newspapers, the argument is made that in order to gain a thorough understanding of political history and philosophy a holistic approach should be adopted, one which looks at ideas, context, history, artefact, and political praxis.