It is a commonplace that humans are distinguished from other creatures by a technological ability, and man has often been described as a tool-using animal. The distinction is not entirely valid. Some animals do use tools. Chimpanzees are the most often quoted example, stripping a twig to plunge it into an anthill and then eating the tasty termites which cling to the end of it.
A more modern example of tool-using is that of crows living in a walnut avenue in the Japanese town of Sendai. The walnuts are too hard to crack. So the crows have taken to dropping them on a pedestrian crossing where they are crushed by the passing traffic. When it is the pedestrians' turn, the crows fly in to bear off the fragments.
But there is a difference between using a tool which comes to hand, however improbably, and fashioning one for a purpose. Shaping a tool for cutting or scraping (two basic and useful functions) is a difficult task. Such a tool must be made of a hard material, and the hardest material easily available on the surface of the earth is stone. But how does one shape a stone without tools?
The history of human technology begins with the discovery of how to give stone a cutting edge. The type of stone found most suitable for the purpose is flint.
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