““The double-helix has solved all three of the major challenges of genetic physiology using ingenious variations on the same theme. Mirror-image chemicals are used to generate mirror-image chemicals, reflections used to reconstruct the orginal. Pairs used to maintain the fidelity and fixity of information. "Monet is but an eye," Cezanne once said of his friend, "but, God, what an eye." DNA, by the same logic, is but a chemical-but, God, what a chemical.””