The Thinking Foot is a study of history and associations. In method and form it claims to be no more (nor less) than an illustrated essay on the architectural expression of surface. It concentrates on the Earth on which we walk: not the Earth in depth (the underground world) nor the geological Earth, but simply the Earth as visible crust, as surface. The Thinking Foot is indeed about surface and in particular about how this surface was made into a 'civilized' theatre of communal existence. Civilization means turning things, mostly private or wild, into communal or civic use. Untreated surface becomes communal ground through paving. Paving has many qualities. It hardens the ground, it hides the ground, it equalizes the ground and it protects the ground. Aesthetics certainly play an important part in its appreciation, but on the whole paving is intended to be practical; the intention of paving is to be practical and useful. Throughout its evolution paving has proved to be a necessity with very little artistic ambition and almost no depth. It is surface, just that.