The book "Biographical Dictionary of Freethinkers of All Times and Nations" by Joseph Mazzini Wheeler is an important source of information about prominent representatives of freethinkers from around the world. This work collects biographical data on the thoughts, ideas and activities of famous free thinkers of different eras and countries. The author tells in detail about the life path of each individual mentioned in the book, their views on religion, society, science and politics. Through the book "Biographical Dictionary of Freethinkers of All Times and Peoples", the reader can participate in the study of important aspects of the history of freethinking, get acquainted with the key figures of this movement and understand the influence of their ideas on the modern world. The book is a valuable source of knowledge for those interested in the history of philosophy, religion, and secular humanism.