网络是最大的发明 Nearly two thousand years ago, three elderly Chinese men sat in the gardens of Changle Palace, arguing about what was the greatest invention of all time. Tools made of rock, said one, banging his fist on the delicate carved table. Paper, said another, slamming the side of his hand. No, scissors! cried the third, making chopping movements in the air. And so a game was invented. This little tale is an invention too. We do not know exactly when Rock, Paper, Scissors was dreamed up, nor how, since in the time of Han there were fewer ways of recording the events of the day: no photographs , no sound recordings and no reliable method of storing and passing on information . But the fact that the game existed then, and did not before, means that it is an invention. It may not be a contender for the greatest of all time, but rock, paper and scissors most certainly are. Inventions, for the purposes of this debate, are tangibletechnologies and processes, rather than more nebulous things such as ideas, principles and imaginings. Children might feel that Father Christmas is the greatest invention of all time, but we are ruling him out. Tools fashioned of rock, or stone, were probably the earliest inventions worthy of the name. First used in the Paleolithic Age, around 2.6m years ago, they mark an essential progression, from proto-human to human. With simple tools, fashioned by pummelling one piece of rock against another to produce a sharp edge, early man began to shape the world according to his needs, to build rudimentary shelters, to hunt and flay animals for food and clothing. Just about everything else followed from there. There is virtually nothing about the way we live today that would have been possible without those first stone tools. But does longevity alone qualify stone tools for the crown? Im not convinced; theirs was a long, slow grind to efficacy, and in most forms theyve long been eclipsed. The blade, howeverof which scissors are just a manifestation, albeit an ingenious onehas been in constant use since it was first invented at the start of the Ages of Metal, some 400,000 years ago. Think of knives, swords, spears, axes, the guillotineuh-oh. Although we depend on the blade for much of what we now take for granted, from cutting up our food to making the electronics which crowd our daily life, theres a little too much of the chop and slash about blades to make them my greatest of all time. So how about the third of our Chinese gents suggestions: paper? Invented by an imperial courtier named Tsai Lun in 105AD, it was deemed so precious and important that successive Chinese dynasties kept it secret for six centuries. Not something that the Dragons of todays Den, with their greedy eyes and piles of cash, would be inclined to do. It is thanks to paper that we know about its invention. The ability to keep a written record is the foundation of mass learning. While the alphabet was invented around 2,000BC , it wasnt easy to pass around heavy stone tablets, or to manufacture and preserve papyrus scrolls in great numbers. The invention of paper led inexorably to books, the printing press, newspapers and magazines, to sacred texts, art, photography and music scores, handed down through generations. And yet, here we are at the dawn of what may, finally, become a paperless society. Paper may cover stone, but it is cut by scissors and burned by fireanother of the foundations of our society.