A strong interest for lexicography is one of the distinctive aspects of the researches conducted by ILIESI, celebrating this year the 50th anniversary of its foundation. In this book lexicography meets the history of the ideas and the vocabulary of culture. The two nouns chosen as subjects of the conference cover a wide semantic area, explored starting from ancient philosophy, across all the main achievements of the Renaissance and modern thought, up to the crucial results of Kant’s philosophy and German idealism.