In short, from a global perspective, it is on the surface of the world, not at its centre, that life is lived. As a foundational level of ‘physical reality’, this surface is supposed already to have been in existence long before there was any life at all. Then somehow, through a series of events of near-miraculous improbability, there appeared on it first life and then, very much later, consciousness. These appearances are commonly pictured in terms of the addition of extra layers of being to that basic layer represented by the earth’s surface: hence the tripartite division into lithosphere, biosphere and noosphere, corresponding respectively to the inorganic substance of rocks and minerals, the organic substance of living things and the superorganic substance of human culture and society. The world depicted in Figure 12.4, insofar as it corresponds to ‘planet Earth’, consists of pure substance, physical matter, presenting an opaque and impenetrable surface of literal reality upon which form and meaning are overlain by the human mind. That is to say, meaning does not lie in the relational context of the perceiver’s involvement in the world, but is rather inscribed upon the outer surface of the world by the mind of the perceiver. To know the world, then, is a matter not of sensory attunement but of cognitive reconstruction. And such knowledge is acquired not by engaging directly, in a practical way, with the objects in one’s surroundings, but rather by learning to represent them, in the mind, in the form of a map.