while we know that this whole vastness of knowledge is not yet a complete understanding of life and the world, and while we are sure that in tens of thousands of years people will still be needing to study nature and make discoveries, in any case we must own that all this knowledge greatly exceeds the powers of a single mind. At this point, in astonishment we ask: how did all this knowledge accumulate? and, with a sense of dread, we think: will our successors be able to add something of their own to this immense treasury, and if so, how?
No less imposing is the number of inventions; the machines, several of which annually augment the stock, and the new materials that greet our eyes, spread so quickly and provide such great services. It will suffice to mention here, as examples of machines: the telegraph, steam-powered machines, sewing machines; and, of materials, lighting gas, rubber, kerosene, and so on. Who of us, while watching a machine, has not marveled at the precision of its movements, of its profusion of wheels large and small, of its rods and other components? who has not asked: what good genius whispered to man the idea of building this extraordinary thing? and will this genius be equally propitious to our successors?
Man has posed such question from the earliest times and has sometimes arrived at peculiar conclusions. The ancients, for example, held that the goddess Ceres taught people husbandry; and that a hero-demigod, Prometheus, stole fire from heaven and brought it to Earth.
Today people no longer believe that gods taught useful inventions to landed proprietors; they know that man invented fire, man invented agriculture, just as man invented the telegraph and the locomotive.
