We have accumulated a massive collection of "information" to which we may have "access." But this information, by being accessible, does not become knowledge. We might find, if such a computation were possible, that the amount of human knowledge over many millenia has remained more or less constant -- that is it has always filled the available mental capacity -- and therefore that learing invariably involves forgetting. To have the Renaissance, we had to forget the Middle Ages. To the extent that we have learned about machines, we have forgotten about plants and animals. Every nail we drive in, as I believe C.S. Lewis said, drives another out.
-- Wendell Berry, Our Only World: Ten Essays
This brings to mind another passage I read in Jared Diamond's Guns, Germs, and Steel. Diamond was doing research work in New Guinea and was traveling in the jungle, a group of natives as his guide. The natives were picking mushrooms to eat and Diamond nervously commented that a lot of mushroom species were poisonous and that he hoped his companions knew which were which. His guides laughed at him and proceeded to give him a very long and detailed lesson about every mushroom species native to that jungle, its characteristics and growing patterns, and whether it was safe to eat or not.
Diamond sheepishly realized that the people he was with spent their entire lives in the jungle. They didn't have the book knowledge he had as a university professor, but they weren't stupid either. They had a deep knowledge about the land they lived on, an intimacy with the jungle that is unknown among "civilized" folk.
The point is that people have not necessarily gotten smarter over the centuries, as we arrogantly assume. People of every era have a fund of knowledge appropriate for their own time, and can be deeply knowlegdable about the things that concern them most. A Roman soldier may have known nothing about an electron, but could probably kill a cow and cure the leather to make a pair of sandals. A French peasant may not have been able to describe the theory of evolution, but he could take an ax into the woods and come back with the material needed to fix a hole in his roof. He could probably identify every tree in the forest and tell you which wood would be best for roofing, how old the tree needed to be, if it would be best to allow the wood to dry before use, or if it could be applied green.
As Berry notes, we only think we are smarter than the people who burned witches. Maybe we are, but maybe we aren't. But we do have nuclear weapons.