To the delight of scholars, Aristotle's surviving writings are both extensive and obscure. One of the sources of this obscurity is familiar to us from scholastic philosophy: the arguments often seem to meander through a nearly featureless theoretical countryside. In this barren realm we find few familiar landmarks, so that even with the road map provided by the arguments, we are often unable to tell where we are headed or why we have taken a turn.

The first part of this chapter briefly sketches out some important features of the theoretical road map as it is presented in Aristotle's earlier, logical works, the Organon. This is not intended as a primary study of those features. Those seeking that can find other, far more detailed, discussions. My purpose is to introduce some key notions and to point out their limitations.

In the second I turn to the Physics and to questions about the geography and population of the landscape there. Some of these features are quite basic to Aristotle's philosophical concerns yet are never explicitly discussed by him; others he touches upon only tangentially or in unexpected contexts; still others he discusses over and over again. None of them is in any way esoteric: they are all homely features of the world that have been noted by ten year olds throughout history – things like spiderwebs, earth, houses, sheep, and ponds. To understand Aristotle's system, we need to see how these things fit into it.