practical heat of industry.°° Ever-more efficient use of iron, of steam, of electricity all reflected a virtuous loop of theory and practice, between the lab and the market, the scientist and the businessman. This fusion of the instinct for competition, for constant new innovation, delivered the modern world you and I live in today. “All fixed, fast-frozen relations,” Karl Marx and Friedrich Engels wrote in 1849 about the speed of this change, “are swept away. All new-formed ones become antiquated before they can ossify. All that is solid, melts into air.”?” As more people “dared to know’, the big ideas and big thinkers attracted an audience. Arguments started. New ways to record and share the answers appeared too. Locke or Newton or Darwin were as notable for the crowd of debating, curious citizens they attracted as for their ideas. Such contentious discussions were designed to elicit truth, to give individuals that same shocking sense Luther had felt on discovering a powerful idea by himself; but as important was that these debates were recorded - written and then distributed in journals, books and letters. For most of history, after all, knowledge suffered from its own fragility and asymmetry: There was always a chance, maybe even a likelihood, that some important insight would be lost in a plague, strangled as heretical, burnt up in a library fire, or dissolved by some military misfortune. This is why, for instance, we have almost all of Shakespeare and why we are missing so much of Sappho. Widespread knowledge changed this. A solid, inarguable base endured. “If 1 have seen further,” Newton famously wrote, “it is because I have stood on the shoulders of giants.” Those shoulders for Netwon were enshrined in libraries, scientific journals and the massive sense of what had come before swaddled in the Cambridge walls that surrounded him. In this sense, the preservation and advance of knowledge, the new symmetry, was not only the largest shift of power in history. It