If the brain were so simple we could understand it, we would be so simple we couldn't.

Breathing air is a liberating experience. It freed our ancestors from the constraints of staying wet or having to remain within easy reach of water for refuge, respiration or reproduction. But the biggest change it made in our lives was to expose us to a whole new range of sensory experience.

Dancing is surely the most basic and relevant of all forms of expression. Nothing else can so effectively give outward form to an inner experience. Poetry and music exist in time. Painting and architecture are a part of space. But only the dance lives at once in both space and time. In it the creator and the thing created, the artist and the expression, are one. Each participates completely in the other. There could be no better metaphor for an understanding of the mechanics of the cosmos.

The limits of sensory evolution in fish are defined very largely by their habitat. Water is physically supportive, carries some kinds of odour well, and is kind to sound - letting it travel several times faster than air will allow, but it inhibits other more personal kinds of communication.

Even in the lives of fishes, sensation is seldom a matter of one thing or another. Senses overlap. The lines between them often tend to be blurred, and the best that we can manage, by way of description from the outside, is to say that the senses of fishes appear to dominate one at a time.

Before sight and sound hijacked our attention, we shared with all life a sort of common sense, a chemical sense that depended on direct contact with matter in the water or the air.