As vast and complex as it is, the world is bound by a certain arrangement that brings it to a cohesive whole. Much of what is known about the universe is confirmed by what is physical and perceptible. In the same way, there are many things that exist in the world that are intangible and cannot be readily seen, beginning with the atom. In Book IV, Lucretius draws on this point by stating that things can either pass through another object such as glass, break upon impact with another object such as rock, or rebound from other objects, such as a mirror. This affects the means by which images of unseen objects are produced, but in the case of mirrors, their smooth surface can generate a reflection. It is from this angle, or view of the world, that images become identifiable. As Lucretius puts it, "suddenly you place a thing in front of the mirror, at once its image appears; so you may know that from the surface of things there is a constant and perpetual flow of thin shapes and thin tissues everywhere," (IV, Lines 155-159). Through this analogy of the mirror, it is evident that everything in the world is interconnected. Every working of nature is mirrored throughout the whole universe, pushing one beyond the limits of knowledge, as well as driving them to the ultimate extent of what is humanly possible to understand. .
In, "On the Nature of the Universe," Lucretius grounds his reasoning with a two-sided philosophical approach. He says that atoms exist infinitely, though they are restricted by how much they can vary in shape, size, or weight. These limited structures and movements grant them their distinctiveness because of the fact that they all travel at equal speed, but in different magnitudes. This parallels to Lucretius's explanation of the body and mind existing as one, asserting that 'interwoven are the elements from their origin, which constitute their common life; and neither body nor mind has power of feeling, one without the other, but by the joint movements of both united sensation is kindled for us in the flesh" (III, Lines 331-336).
