The speech is the place where humanity was born and where human beings come into the world every day. It is divided into thousands of languages, placed at the basis of our evolution. Over the millennia it has brought us from nature to culture, from instinct to reason, giving birth to the life of the spirit every day. Always the same and always different, it is an indispensable foundation of all knowledge and all sciences, from ancient to modern times. The book examines some emblematic cases (from China to Greece, from the Middle Ages to the modern scientific revolution) up to the idiom of the planetary man we are becoming, capable of projecting his own borders beyond Earth and our solar system. Carlo Sini has been measuring himself for some time with fundamental themes of humanity, starting with language. His acute gaze crosses the history of peoples and ages, reaching the point of questioning the man itself.