Affecting us in our physical reality, or the way we live, technologies inevitably affect us in our mental reality, or the way we perceive the world and behave rationally. Stone fences built in the Bronze Age in Cornwall established the pattern of fields to this day when they are still in use, particularly in the Penwith peninsula. Thus the material used in the construction of a technology often determines the duration of its culture. We can suppose that if the fences had been made of wood, the boundaries of the fields might have changed a long time ago. But the material of stone added a curious time bias to this largely space-biased medium - by Innis - enhancing a tradition of valuing the past and fostering conservative behavior.