Most of us find the ordered symmetry of a formal herb garden pleasing. The artful arrangement of straight lines and curves satisfies both the eye and the brain, and even gardeners who prefer a more informal style usually admit an admiration for a well-groomed formal garden. For the formality of clipped hedges and neat paths with tidy planting can produce an atmosphere of peace and tranquillity in a garden - as if man and the unruly forces of nature have come to terms with each other to produce harmony.