The beginning is easy. We recognize as belonging to culture all the activities and possessions which men use to make the earth serviceable to them, to protect them against the tyranny of natural forces, and so on. There is less doubt about this aspect of civilization than any other. If we go back far enough we find that the first acts of civilization were the use of tools, the gaining of power over fire, and the construction of dwellings. Among these the acquisition of power over fire stands out as a quite exceptional achievement, without a prototype;[11] while the other two opened up paths which have ever since been pursued by man, the stimulus towards which is easily imagined. By means of all his tools, man makes his own organs more perfect—both the motor and the sensory—or else removes the obstacles in the way of their activity. Machinery places gigantic power at his disposal which, like his muscles, he can employ in any direction; ships and aircraft have the effect that neither air nor water can prevent his traversing them. With spectacles he corrects the defects of the lens in his own eyes; with telescopes he looks at far distances; with the microscope he overcomes the limitations in visibility due to the structure of his retina. With the photographic camera he has created an instrument which registers transitory visual impressions, just as the gramophone does with equally transient auditory ones; both are at bottom materializations of his own power of memory. With the help of the telephone he can hear at distances which even fairy-tales would treat as insuperable; writing to begin with was the voice of the absent; dwellings were a substitute for the mother’s womb, that first abode, in which he was safe and felt so content, for which he probably yearns ever after.