Bronowski wrote the book (The Ascent of Man). Bronowski is interested in architecture, and some of the great inventions like the arch that made the construction of Roman aqueducts and medieval cathedrals possible. What is it about the arch that made such new and remarkable structures possible? Describe the buildings of the Greeks and Incas, and how they were limited compared with what the Romans and later civilizations were able to construct thanks to the arch. Why does Bronowski entitle this episode "The Grain in the Stone"? What do you think he means by this, and what does it have to do with architecture?