Science, ever since the time of Arabs, has had two functions: to enable us to know things, and to enable us to do things. The Greeks, with the exception of Archimedes, were only interested in the first of these. They had much curiosity about the world, but, since civilized people lived comfortably on slave labour, they had no interest in technique. Interest in the practical uses of science came first through superstition and magic. The Arabs wished to discover the philosopher’s stone, the elixir of life, and how to transmute base metals into gold. In pursuing investigations having these purposes, they discovered many facts in chemistry, but they did not arrive at any valid and important general laws, and their technique remained elementary.
However, in the late middle Ages, two discoveries were made which had a profound importance: they were gunpowder and the mariner’s compass. The main importance of gunpowder, at first, was that it enabled central governments to subdue rebellious barons. Magna Carta would have never been won if John had possessed artillery. But although in this instance we may side with the barons against the king, in general the Middle Ages suffered from anarchy, and what was needed was a way of establishing order and respect for law. At that time only royal power could achieve this.
Long before the use of electricity as a source of power, it was used in the telegraph. This had two important consequences: first, message could now travel faster than human beings; secondly in large organisations detailed control from a centre became much more possible than it had formerly been.