A symbol is a sign for the supersensible reality that can be perceived through the senses. Symbolic thought is possible because the levels of being are modeled by the analogy. Thus, pure, suprasensible being mirrors itself in sensible things that point to intelligible reality and make it accessible. Light refers beyond itself better than any other sensorial thing; it is the most patent sign of suprasensible reality. The Greeks recognized this symbolic power of light from the beginning.