What accounts for the repeated misfortunes of the rainbow in figurative painting? It may well be that an excess of ostentatious cuteness, by its provocative ready-made, found-it-so nature, alienates the true painter. But more likely, there is another cause: what prevents the integration of a rainbow into a painting is not an insurmountable technical difficulty, but rather the admission it represents, of the painter's failure to subject all natural elements, without exception, to the organized arbitrariness of their personal vision. The rainbow is the introduction, in the midst of a colorful symphony entirely written in a subjective key, of a dioptric formula resistant to any substitution. And such prohibitions signified by painting also apply to literature.