" the congruence of the complement..."See in text(Text of the Poem)
The “congruence of the complement” is a geometric theorem which states that two angles which complement the same third angle are identical to each other. Such a theorem is equivalent to the steamroller’s understanding of the world, in which like objects are lumped together; differences are lost. Through such mathematical thinking, the world is made abstract.
The science of sensory perception, “aesthetic” refers to a system of principles for the appreciation of the beautiful. This term underscores the tension in this poem between a theoretical approach to the world and an experiential approach to the world. A theoretical viewpoint believes that it can classify beauty and objectively understand it using a set of principles.