Indeed, compared with Berkeley's eye-picture of the world, that of Reid is in every respect a 'limb-picture'. For where he seeks for the origin of our naïve assurance that a real material world exists, there he reverts - guided by his common sense - to the experiences available to the soul through the fact that the limbs of the body meet with the resistant matter of the world. And whenever he turns to the various senses in his search, it is always the will-activity of the soul within the sense he is investigating - and so the limb-nature within it - to which he first turns his attention. Because, unlike Berkeley, he takes into account the experiences undergone by the soul when it leaves behind its primal condition, Reid does not fall into illusion, but discovers a fundamental truth concerning the nature of the world-picture experienced by man in his adult age. This, in turn, enables him to discover the nature of man's world picture in early childhood and to recognize the importance of recovering it in later life as a foundation for a true philosophy.