“Art is thinking in images.”
This is the opening line of the text and it is situated within quotation marks as part of the presentation in order to convey the full depth of its significance. Just in case that depth is not appreciated, however, it will be repeated verbatim twice more and referenced or alluded to multiple times throughout the opening chapter. As such, this quote should not be lightly regarded or easily overlooked. The author is definitely trying to make an impression upon the reader with such a commitment to recurring and repetition. Such a technique is one to pay close attention to and learn from. As to what is specifically being argued or asserted with this opening, the author himself devotes an entire chapter, so it would hardly be efficient to condense things here.
A literary work is pure form. It is neither thing nor material, but a relationship of materials. And, like every relationship, this one too has little to do with length or width or any other dimension. It's the arithmetic significance of its numerator and denominator (i.e., their relationship) that is important.
The point being made here is directed toward judgment. After having already explained how certain genres and types of prose are mechanistically constructed, the author reaches the point of explaining that none of these differentiations or divergences really count relative to the fundamental point of literature. Taste can lead one to prefer one sort of story over another, but objectively considered there is little point in arguing for the aesthetic or artistic pre-eminence of one over another. The history of prose is one in which forms have built upon themselves, sometimes creating new ones out of the raw material of earlier forms and sometimes by obliterating those earlier forms completely. The point is always evolution rather than stagnation.
The unity of a work of literature is more likely than not a myth.
At this point, the narrator’s theory of prose diverges wildly from the larger conventional view. In fact, most literary analysis is conducted upon an unspoken agreement beforehand that a work of literature is unified either purposely or unconsciously. Which path one chooses to go down in their analysis depends greatly upon whether they are actively pursuing the suggestion that it is the author’s conscious drive which accounts for the unity or whether the unity is arrived at in spite of what the author desired. Either way, however, the fundamental underlying assumption is that unity exists. Clearly, the theoretician here disagrees.