"The evolution of all things animate or inanimate takes place within a sea of forces. Some of these forces are dominant, some are scarcely there at all, but all exert some influence on the changing form. The force might be a necessity for the placement of leaves to maximize sunlight or it might be a compression of space, a surface stress, heat, infusion with another substance, vibration, or sonic disturbance, wind, torsion, electrical charge, gravitational pull, or any number and combination of other mechanical or chemical forces. The substance can only respond and its evolving form is a reflection of the forces, like a patch of froth on a slowly winding river revealing the currents and countercurrents. When the forces are complex and constantly shifting, the developing form is unpredictable, like an old pear tree that has been broken, pruned, and buffeted by the elements, or the skin of an aged elephant. But when the forces are more constant and predictable the forms evolve into rhythm, pattern, and symmetry."