Blue flower, red thorns! Blue flower, red thorns! Blue flower, red thorns! Oh, this would be so much easier if I wasn't color-blind!
Foster's Chapter 22 was a chapter in which he explained the need, as an author, to sometimes make the symbolism extremely obvious. For his example, he brought up the play Oedipus Rex and how blatant the play made Oedipus' blindness, eventhough he had perfect eye sight, using a blind man who could see more than what met people's eyes.
It is necessary to do this so that you can add a deeper meaning for all of your readers including those who do not use close reading techniques. By doing this, the story will inevitably become something more for those who do not look into the symbolism in books. As an English major, I find that this is an extremely valuable piece of information because it is something that I've never taken into account before and probably wouldn't have considered until it was brought to my attention. I'm very glad that I read this chapter in my freshman year instead of finding out after being half way through my career.