An essential theme in Through the Looking-Glass is the ability of language to bring order to a chaotic reality. The influence of words is evident in the nursery-rhyme characters, whose actions are dictated by their rhymes. Tweedledum and Tweedledee engage in a fight over a rattle not by choice but because the rhyme compels them to do so. Similarly, Humpty Dumpty believes the king will send his men to assist him simply because the rhyme dictates it.

The way characters wield language also defines their identities. Humpty Dumpty tells Alice that when he uses a word, "it means just what I choose it to mean—neither more nor less. . . . The question is which is to be master—that's all." Perched on his wall, Humpty is a snob. He believes his refined diction elevates him to the upper class, allowing him to "lord" over others. He thinks his words grant him the authority to intimidate. However, like Humpty's fragile eggshell exterior, this power is tenuous. Human efforts to impose order on nature through language are equally delicate. Alice may decide to tell Kitty that her adventures were a "nice dream," but she had previously exclaimed in frustration at the chaotic banquet, "I can't stand this any longer!" Through language, humanity attempts to create meaning and order in an amoral, chaotic world, but such constructs of human law and social norms are inherently unstable.

"Beware the Jabberwock, my son!/ The jaws that bite, the claws that catch!"
Carroll also illustrates, through various episodes in Through the Looking-Glass, that language in our world is often arbitrary and can reveal careless thinking. In the garden, a tree in danger barks, "Bough-wough." Carroll highlights the odd connections in our language between tree bark and dog barks, tree boughs, and a dog's bow-wows. In another scene, a frog cannot comprehend why anyone would answer the door unless it was posing a question. He distrusts words that are poorly defined and inconsistently linked to reality. In yet another episode, Alice tells the King she sees nobody on the road, and he praises her for her excellent vision in seeing Nobody.

While language can construct a delicate order for the world, it can also simplify it from a realm of poetry and imagination to one dominated by logic and control. For instance, when the Gnat asks Alice which insects she "rejoices" in, Alice responds, "I don't rejoice in insects at all . . . . But I can tell you the names of some of them." The Gnat inquires if the insects respond to their names, questioning whether the names benefit the insects in any way. Alice answers that names are useful only to the person who assigns them, thereby exerting control over other beings. As Alice begins to list some insects, the Gnat provides whimsical definitions for the arbitrary names: "a snapdragon-fly. Its body is made of plum pudding, its wings of holly-leaves, and its head is a raisin burning in brandy." The poetic nature of the Gnat's descriptions eludes Alice; she can only theorize why insects "are so fond of flying into candles."

The Gnat episode also highlights another significant power of language: the power of names. Alice overlooks the Gnat's point that names diminish and signify another's control. The Gnat asks if she would willingly give up her name. She replies, "No, indeed." When the Gnat notes that her governess could then only call her "Miss" and could "miss" her lessons, Alice dismisses this as a poor joke. The Gnat then mourns her lost imagination and innocence.

Later in her journey towards adulthood, Alice...