The idea of a divine "illumination" in the mind occurs in both philosophical and religious contexts. Often it forms one of the links between the two types of thought, and sometimes it bears distinctly religious overtones even in its more philosophical applications. This is one of the characteristic features of the theory of illumination in the thought of Plato, where it played, for the first time in its long history, a major part. Plato, like many other thinkers, creative artists, prophets, and mystics, spoke readily of the sudden flash of understanding or insight in the mind as a flood of light (see, for example, his Seventh Letter, 341C, 344B). The image is, indeed, one that occurs naturally in many languages and is especially apt for the description of insight thought to have been achieved as a result of external aid of some kind, of an "inspiration." The language...