15 - Book 5, pt 3 - The rudeness of the early life of men. The invention of speech.The discovery of fire, the progress of society. The rise of religion from ignorance of natural causes. The discovery of metals and the progress of the arts.

Summary: 15 - Book 5, pt 3 - The rudeness of the early life of men. The invention of speech.The discovery of fire, the progress of society. The rise of religion from ignorance of natural causes. The discovery of metals and the progress of the arts.