A Square lists a third and final method of recognition, that of sight, which is practiced only by the higher classes and depends on the naturally abundant fog in Flatland. By comparing relative dimness and brightness of the sides of another, Flatlanders can infer the configurations of each other.
Although light and shade (higher knowledge) do not exist in Flatland, they can compare relative brightness in order to infer another’s shape, which speaks to the way in which knowledge always has the potential to seek higher truths. However, the upper classes exclusively keep this knowledge to themselves, again maintaining the social hierarchy.
A Square explains this with a specific example of discerning between a merchant who is an equal-sided triangle and a pentagonal physician. While the sides of the merchant recede rapidly into the fog, the physician’s sides shade away less rapidly to and, thus, are distinguishable from the merchant (two exemplary figures are included).
Note here again how Abbott uses analogy (a merchant and a physician) to illustrate how in Flatland figures are distinguished by social status. In addition, analogy is aided by another illustration.
In Flatland, sight recognition is considered an Art form because of the inherent difficulties involved in the act. The fact that one may be approached from another’s side (instead of his angle), as is illustrated, and the motion of polygons makes sight recognition even more complex of a method.
Because of the inherent complexity involved with sight recognition, the higher classes are able to easily keep the method from the lower classes.
Therefore, A Square states that the higher classes prohibit the practice of “feeling,” and from early on, their children are sent to Seminaries (and not Public Elementary schools) to learn the art of “Sight”. On the other hand, “sight” is an unattainable skill to the lower classes. Thus, the children of the poor learn how to “feel” at the early age.
Not only are Flatlanders socially hierarchized by configuration, but they are also kept in distinct social classes based on what they know (which is, of course, only taught to them based on their configuration, again perpetuating the status quo).
A Square states that there is a Final Test of sight recognition given to the polygonal class at the University. He explains that the statesmen have dictated that those who fail the test be either imprisoned for life or put to death, since it is from these specimens that leaders of past rebellions arose.
Holding official examinations and executing those who fail is another method that the higher classes maintain power, by destroying any potential sources of rebellion. Once again Flatland is shown to be a rather terrifying place to live, despite A Square’s matter-of-fact tone in describing it.