Freedom manifests itself as a concept used for man as a rational being. The concept appears differently in different fields. While one can talk about freedom of will, which is considered the opposite of the philosophy of necessity in a philosophical sense, it is also possible to talk about individual and social freedom. It is possible to say that the concept of individual freedom makes itself felt stronger with the liberal understanding. Freedom of thought, expression and discussion, depending on the concepts of individual and social freedom, emerges as one of the fundamental problems of today. Today's problem is related to the social pressures and the obstacles and limitations of different centres of authority on the individual and his/her freedom and its integral parts. This study is intended to reveal the nature and limits of freedom of thought and discussion in the context of the freedom-authority relationship as found in the thought of J. S. Mill, the author of the first serious, manifesto-like work written on freedom. He attaches great importance to the nature and limitation of the ruling power, which has an oppressive and restrictive structure on individual freedom, within the framework of freedom of thought and discussion.