The ancient Celts often used eternity knots to represent stages of man. Circles represent unity. Squares are shield knots, symbols of protection from spirits or malevolent influence. Interlaced units usually represent relationships, or emphasize the interdependence of mankind and nature. Deborah wanted to create something that would symbolize the cycles of life. She alternated round eternity knots with the squares to ward off negative influences and thus represent the continuum of life and all its promises.