There is an inside and an outside to every form. When they are in special accord, as for instance a nut in its shell or a child in the womb, or in the structure of shells or crystals, or when one senses the architecture of bones in the human figure, then I am most drawn to the effect of light. Every shadow cast by the sun from an ever-varying angle reveals the harmony of the inside to outside. Light gives full play to our tactile perceptions through the experience of our eyes, and the vitality of forms is revealed by the interplay between space and volume

Extract from Barbara Hepworth: "Carvings and Drawings", (from Chapter 1: The excitement of discovering the nature of carving, 1903-1930), with an introduction by Herbert Read, London, 1952