observation of rocks and outcrops. The interplay of internal and external sources—of theory informed by metaphor and observation constrained by theory—marks any major movement in science. We can grasp the discovery of deep time when we recognize the metaphors underlying several centuries of debate as a common heritage of all people who have ever struggled with such basic riddles as direction and immanence.

On Dichotomy

Any scholar immersed in the details of an intricate problem will tell you that its richness cannot be abstracted as a dichotomy, a conflict between two opposing interpretations. Yet, for reasons that I do not begin to understand, the human mind loves to dichotomize—at least in our culture, but probably more generally, as structuralist analyses of non-Western systems have demonstrated. We can extend our own tradition at least to the famous aphorism of Diogenes Laertius: "Protagoras asserted that there were two sides to every question, exactly opposite to each other."

I used to rail against these simplifications, but now feel that another strategy for pluralism might be more successful. I despair of persuading people to drop the familiar and comforting tactic of dichotomy. Perhaps, instead, we might expand the framework of debates by seeking other dichotomies more appropriate than, or simply different from, the conventional divisions. All dichotomies are simplifications, but the rendition of a conflict along differing axes of several orthogonal dichotomies might provide an amplitude of proper intellectual space without forcing us to forgo our most comforting tool of thought.

The problem is not so much that we are driven to dichotomy, but that we impose incorrect or misleading divisions by two upon the world's complexity. The inadequacy of some dichotomies rests upon their anachronism. Darwin, for example, built such a prominent watershed that we tend to impose the conventional dichotomy